DIY quadratic diffuser
- Thread starter RICK FITZPATRICK
- Start date
Still trying to find out from the resident wood experts --
If I build the blocks using lengths cut from 2x2 lumber and attach the end to a base -- what's the best way? In particular, if I use wood glue, would I need to clamp the pieces together while they dry?
How about if I use a thin base, like a piece of wood paneling, then put glue on the end of the 2x2 (and sides, where it is next to other blocks), then put it in place and put a 5/8" staple through the paneling into the block from the back to hold it while it dries?
Crazyily yours,
-lee-
If I build the blocks using lengths cut from 2x2 lumber and attach the end to a base -- what's the best way? In particular, if I use wood glue, would I need to clamp the pieces together while they dry?
How about if I use a thin base, like a piece of wood paneling, then put glue on the end of the 2x2 (and sides, where it is next to other blocks), then put it in place and put a 5/8" staple through the paneling into the block from the back to hold it while it dries?
Crazyily yours,
-lee-
foreverain4
New member
if it is 2x2 inches, use screws. it would definately hold better than a staple until the glue dries. lay out a 2x2 grid the same on both sides of your backer piece. that way you know where to screw.
lynn
lynn
RICK FITZPATRICK
New member
New DIY diffuser...
Hello gatorhaus, yea, like foreverain4 said screws. And I'll tell ya something else
Heres some additional stuff on the 2x2 random diffuser. I'm starting a new thread cause this one isn't quadratic. Besides this thread is long enough as it is. So see the new on, as it relates to your application.
fitz
Hello gatorhaus, yea, like foreverain4 said screws. And I'll tell ya something else
Heres some additional stuff on the 2x2 random diffuser. I'm starting a new thread cause this one isn't quadratic. Besides this thread is long enough as it is. So see the new on, as it relates to your application.
fitz
I *like* long threads.... if they have info in them! 
I'm not sure the 2-D art diffusor is the same as the 2-D BBC diffusor -- they don't have repeating elements the same way.
I was hoping you guys wouldn't suggest screws -- they seem like they'll be a bit of a pain, but, on the other hand, I don't want blocks falling off and hitting the artists! If I use a screw, do I need to pre-drill a hole first, or just screw it in? What kind of screw -- wood screw or deck screw? Seems like deck screws can be had nice and cheap....
Thanks,
-lee-
I'm not sure the 2-D art diffusor is the same as the 2-D BBC diffusor -- they don't have repeating elements the same way.
I was hoping you guys wouldn't suggest screws -- they seem like they'll be a bit of a pain, but, on the other hand, I don't want blocks falling off and hitting the artists! If I use a screw, do I need to pre-drill a hole first, or just screw it in? What kind of screw -- wood screw or deck screw? Seems like deck screws can be had nice and cheap....
Thanks,
-lee-
RICK FITZPATRICK
New member
Hello laptoppop, ok, first lesson in Studio building. Are you ready for a LONG reply?
Do you have a drill? How about driver bits. Phillips? Straight? Throw them away
Is there a Ace hardware or Home Depot nearby or other fastener store nearby?
Do this. Ask around for SQUARE RECESS SCREWS. I buy them in bulk at ACE but not all the ACE stores carry them. They look like a sheetrock screw or a deck screw, but instead of a phillips indentation in the head, they have a SQUARE HOLE in the head. Once you find and buy them, buy a couple of #1 and #2 SQAURE HEAD driver bits.
If not, call around your area if need be. Once you have tried these, you will never drive a phillips again!! If you have never drove a screw with a drill and driver bit you will wonder how you ever got along without them. Heres why.
Usually, in order to start a PHILLIPS screw usinging a drill/driver bit, you can drive a screw into a piece of material, by simply placing the screw on the driver and placing the drill/driver/screw against the face of the material, PUSH as you start the drill, and the threads of the screw must bite into the face AFTER it has penetrated the surface, as the threads are designed to engage the material as it FEEDS into the material. This does two things. I pulls itself into the material, and as it does it is pulling away from YOU and it must COMPRESS the material that the screw shank is forcing out of the way as it digs deeper and deeper. At least thats the theory. Heres the truth.
As you push the drill, the bit, must fit exactly the phillips INDENTATION in the screw head or it will begin to wobble.(Don't use a REED and PRINCE bit) When it wobbles, you loose the center of the centrifical lever. In otherwords, the centerline of the drill drifts off center, and if the screw has not entered the material, will slip, and any fingers in the way recieve what the bit is capable of. Its pointed! OOPS. DAMN THAT HURTS! I see it happen to non Journeyman at work once a month. If your standing on a ladder, trying to drive a 3" screw into an old stud, while holding the screw, your an idiot. Accident waiting to happen.
IF YOU MUST USE PHILLIPS:
Solution #1 Keep phillips bits in GREAT SHAPE. THEY ARE CHEAP.
This is why. When you use phillips bits, especially long ones, the deeper you drive the screw, you are compressing MORE material. It now takes more TORQUE to drive it which now means, you must push HARDER, to keep the bit ENGAGED into the indentation(little X on the head of the screw) or it will CLIMB out of the indentation. The more it climbs out, the less surface area of the indentation X and BIT FLANGE is in contact. Because the bit is TAPERED No contact means you now do two things. You wear the bit MALE flanges and you STRIP the FEMALE indentation flanges. The steel in the screw is much much softer on a common Phillips screw than the bit. The bit is TEMPERED. Much harder steel. Deck screws, Sheetrock screws, machine screws etc are a different alloy, and are less prone to stripping. But then, they DULL the flanges on the driver bit. VOILA! Now you have a dull bit, and a screw half flushed and you can't drive it any further. SHIT. You know either remove it with the bit. It MIGHT WORK but if not, then proceeds to dull the bit in the OPPOSITE direction and strip the screw too.
The next screw you use, NOW will NOT fit correctly. You now have a better chance at striping it as well as dulling the bit even further. Or you use a pair of pliers to back it out, or with harder screws, you knock the head off with a hammer. Or cut it off with dykes or a hacksaw
Solution #2 Use a magnetic driver to hold replacable bits. Buy 5 or 6 replacable phillips bits at the counter. They usually have a JAR of them or some kind of display with Phillips bits by the bulk. (are we spoiled or what!) If you dull one in one whack, REPLACE IT. Now some of you may think I'm crazy, but I build all the time. These are POINTERS only.
Solution #3 Use pilot holes. When you are fastening something to wood with a screw, the threads are what pull the head closer to the surface. IF you are fastening something to wood that has NO HOLE to place the screw through, the threads have to bite into it first. Imagine this. Think of a washer. I use them all the time(more of that in the next installment!Ha!) A washer has a hole. It does two things. First it allows the screw to FREEFLOAT in the hole, and second, compress whatever is below it, as the screw embeds into the SECONDARY surface and pulls up tight. The first surface is the PRIMARY surface, which is the face of the washer that is facing the underside of the screwhead. It could be anything. Another piece of wood, a metal flange, hardware, plastic etc. But imagine its not a washer, but another piece of wood. IF there is no hole through the PRIMARY surface material, then you must either, DRIVE the screw through it or drill a hole large enough for the screw to FREEFLOAT. IF you chose to drive the screw, two things happen. As soon as the threads BITE the primary surface, torque is applied to the item. If you are holding it, say a short piece, it wants to rotate with the screw. BAD NEWS. YOU CAN GET HURT. ESPECIALLY will SHEETmetal. NEVER try to hold a piece of metal with one hand and ENLARGE a previously drill hole to a size larger than 1/4" with the other. Even smaller although its less torque and smaller teeth. Even with variable speed drills(more on them later). A large drill bit will bite into a smaller hole, but if that hole is too small the bit bites, but WILL NOT CUT. The torgue is IMMEDIATLY transmitted to the metal, and can pull from your grip. One revolution of the drill, on a piece 6" long can wreak havoc on your fingers in a BLINK of an eye. Same with anything with no PILOT hole and a screw.
If possible, always drill a PILOT hole THROUGH the primary material. This hole should be a fraction bigger than the screw you are driving so it will FREEFLOAT. Now, place the primary material where needed, insert a screw, and place the bit into its indentation, PUSH to engage the threads into the secondary surface, and start the drill. Keep pushing, but use as much pressure and slow as speed as you need to keep the bit from SLIPPING. OK. Another reason for a pilot hole. IF you manage to drive the screw through the primary material, and it is in position to drive the screw right on into the secondary surface, this is what happens. As the threads touch the secondary surface they do NOT immediatly grab. As the screw rotates, it is now pulled further out of the rear face of the primary material. The longer it takes to grab, the GREATER the distance from the primary rear face to the secondary face will remain when the screw head reaches the primary surface. VOILA! A gap between the two materials. And no matter how hard you try to pull that gap up, the more it wants to strip the screw. Because it can go no deeper into the primary surface. Hmmmm! UNLESS, the primary material is SOFTER than the secondary material. IT MAY strip the primary material away from the threads, which actually creates what you should have done in the first place. A PILOT HOLE ....OR.. Clamp the two materials togeather. Then they act as one piece, like with two pieces of ply, or 2x2's or 2 x anything. Usually you can drive a screw through two layers of 2x if they are held down tight, or clamped or have enough weight to keep the screw driving immedietly through the secondary surface. BUT IN THE CASE OF HARDWOODS, PARTICLE BOARD, MDF, MELIMINE, HARDBOARD, MASONITE, PLEXIGLASS, METAL GLASS, ALUMINUM ETC. ETC. YOU MUST drill a pilot hole. This is why. 2x material such as FIR, HEM FIR, PINE, ALDER, PHILLIPINE MAHOG and other softwoods such as fir ply have fibers which will COMPRESS and TEAROUT. They allow a screw to penetrate easily. The other materials on the other hand will NOT as they either have small fibers and composition whereby the screw shank can not compress the material it is replacing as well, or will not compress it AT ALL, such as plex and metals. These materials must be addressed in a different manner. This is a guideline
IF, the primary surface is a hard material it must have a pilot hole.
If, the primary surface is a softer material than the secondary, you may get away with driving it directly through it into the secondary material. PINE, SHEETROCK, PLYWOOD, 2x fir etc are examples you can drive a screw through
IF the secondary surface is SOFT you can drive the screw directly into the material.
IF the secondary material is HARD you MUST drill a SECONDARY pilot hole. This hole should equal or be a bit larger than the SHANK of the screw, but LESS than the threads. In hardwoods you can fudge and the hole can be slightly smaller than the shank due to minute compression. In that case dip the screw in wax. Ha!
IF the secondary is Particle board it will penetrate with no secondary pilot hole, due to large fibers and the bonding material will compress with it. It will however result in the compressed material LIFTING a dimple of material around the screw shank. IF the primary material is hard, it will also compress this dimple and allow the sufaces to pull up tight. If it is softer, then the dimple will penetrate the primary material. That is assuming you drive the screw to its maximum torque, which is when the screwhead makes contact with the primary surface and the screw will no longer turn. In the case of Phillips screws, this is where an Amateur ruins his first phillips bit. As the head comes to an abrubt halt, because the amateur is not PUSHING hard enough, OR is using MAXIMUM speed on the drill, the momentum of the drill armature, is such that it DOES NOT stop rotating. The bit lifts out, keeps rotating and VOILA! Dull driver. Stripped screw. And the scenario keeps getting worse with each time this happens. But to make matters worse, IF the screw is soft you may pop the screwhead off from pushing TOO hard and TOO fast. See it all the time. This also creates another scenario.
As the head comes in contact with the primary surface, either it will penetrate to the point of self countersinking into the surface(soft materials), or will stop at the point of where the underside of the head, which is tapered, contacts the edge of the pilot hole or selfmade hole and comes to a sudden stop. OR POP! Depending on the above conditions. If it stops, the flat screw head will be above the primary surface. In the case of softwoods, as it countersinks into the material, it too creates a small raised donut of material around the screw. And worse in softwoods, the screw will pull through so fast that a donut forms but then pulls into the hole over the screw head. Which is ok if you never have to remove the screw. If you do that in laminate, when you remove the screw, it now will lift the laminate and break out a large chunk, THEREFORE, the pilot hole should ALSO include a COUNTERSINK. It is not required by anything other than more pulling power is applied as the full surface area of the tapered surfaces of the countersink and screw head(underside) come in contact, flush screw aesthetics, or another surface being fastened over it. Also you can drill the countersink deeper, and place a plug, or cover or putty etc. into it. Ok, you still with me? Ha! Were not done yet.
MDF has other considerations. As a primary surface, you must drill a pilot hole. A counter sink is optional. Depending on you. If the screw is driving into hardwoods as a secondary material, it will countersink itself, but with a LARGE donut. This is because MDF is primarily EPOXY, which is hard. The wood is dust, added for filler. There is nothing to compress. If you drive a screw through a piece of 3/4" MDF, with no pilot hole, the thickness of the panel will increase to compensate for the expansion caused by the shank replacement of material equal to the mass of the replacement. It has to go somewhere. What it does is fracture the bonds between the expoxy and wood dust equal to the screw mass, and spreads this expansion equally through the panel around the screw. It will also form a donut at the point of the screws entry and exit. As I said before. If your fastening something hard or small to it as a (MDF primary material) doesn't matter, as a certain portion will force the thickness to increase on the opposite face of the+ panel. If you then drive the screw on through to a HARDER material, it will recompress the fractures, but then the head may countersink or pop the head. If it is a secondary, you SHOULD use a secondary pilot hole. Especially if the MDF panel is thicker than 3/4. " Usually a screw can be driven all the way through the rear face unless other conditions do not allow it. In that case, the screw only has 3/4" to bite. Panels thicker such as 1 1/2" will bring the screw to a halt before it is fully driven With no secondary pilot, the screw will fracture the bonds, and now the threads have a limited ability to do their intended job, and may even tear out. VOILA!, no holding power. Or, break the screw. Now, MDF edges being used as a secondary surface have one more issue. If you drive a screw into the edge of MDF, you may get away with it if your only going in 3/4". But since the bonds are the weakest at the edge, any deeper than the thickness of the panel will now force the panel to fracture at its weekest point and the panel will split. Now your fucked. Therefore, DRILL A SECONDARY PILOT HOLE DEEPER and use longer screws, Usually, 1 1/2" into an edge.
Solution #5 Buy a set of countersink, primary pilot cutter, drill bits. Usually you only need 2 sizes. #8 and #10. Great if you have a bunch of holes to do, which is not uncommon for panel/fixture/cabinet work. Even in 1/4" masonite. You must drill and countersink. Same with plastics(laminates), plex(requires a special drill bit for large holes) These will drill a primary pilot and countersink into the primary material, and a secondary pilot(smaller) into the secondary material when positioned prior to drilling.
Solution #6
Ok! IF YOU DO manage to find the SQUARE HEAD RECESS screws buy what ever you want to spend. They are usually IN BULK. Say, 1/2 pound each of the smallest(1" probably) up to 3". Cost maybe $10. Be the best $10 you've spent in a while, especially if your a DIY like me, or your a homeowner and build/repair a lot.This is why.
First, SHR screws have 3 things normal Phillips do not have. One is the square recess. It does not allow the bit to slip, unless you do not push. But you don't have to push hard unless the material is hard too! Just push hard enough to keep the bit engaged as it drives into the material. Let the threads do the work.
Second, most shr screws have whats known as "GRABBER" threads. Phillip screws are available with these and are actually called GRABBERS. Thats because the thread goes all the way to the tip of the screw so it IMMEDIATTLY grabs. All the way through.
Third, some shr screws have self countersinking teeth on the underside of the head.
Well, shit, theres my book for the week. Hope this enlightens you to some DIY help in "fastenening" skills. To me, fastenening things togeather is the heart of building. Theres a million ways, techniques, hardware, and processes. I'll post more here as time goes by.
fitz
Do you have a drill? How about driver bits. Phillips? Straight? Throw them away
Is there a Ace hardware or Home Depot nearby or other fastener store nearby?
Do this. Ask around for SQUARE RECESS SCREWS. I buy them in bulk at ACE but not all the ACE stores carry them. They look like a sheetrock screw or a deck screw, but instead of a phillips indentation in the head, they have a SQUARE HOLE in the head. Once you find and buy them, buy a couple of #1 and #2 SQAURE HEAD driver bits.
If not, call around your area if need be. Once you have tried these, you will never drive a phillips again!! If you have never drove a screw with a drill and driver bit you will wonder how you ever got along without them. Heres why.
Usually, in order to start a PHILLIPS screw usinging a drill/driver bit, you can drive a screw into a piece of material, by simply placing the screw on the driver and placing the drill/driver/screw against the face of the material, PUSH as you start the drill, and the threads of the screw must bite into the face AFTER it has penetrated the surface, as the threads are designed to engage the material as it FEEDS into the material. This does two things. I pulls itself into the material, and as it does it is pulling away from YOU and it must COMPRESS the material that the screw shank is forcing out of the way as it digs deeper and deeper. At least thats the theory. Heres the truth.
As you push the drill, the bit, must fit exactly the phillips INDENTATION in the screw head or it will begin to wobble.(Don't use a REED and PRINCE bit) When it wobbles, you loose the center of the centrifical lever. In otherwords, the centerline of the drill drifts off center, and if the screw has not entered the material, will slip, and any fingers in the way recieve what the bit is capable of. Its pointed! OOPS. DAMN THAT HURTS! I see it happen to non Journeyman at work once a month. If your standing on a ladder, trying to drive a 3" screw into an old stud, while holding the screw, your an idiot. Accident waiting to happen.
IF YOU MUST USE PHILLIPS:
Solution #1 Keep phillips bits in GREAT SHAPE. THEY ARE CHEAP.
This is why. When you use phillips bits, especially long ones, the deeper you drive the screw, you are compressing MORE material. It now takes more TORQUE to drive it which now means, you must push HARDER, to keep the bit ENGAGED into the indentation(little X on the head of the screw) or it will CLIMB out of the indentation. The more it climbs out, the less surface area of the indentation X and BIT FLANGE is in contact. Because the bit is TAPERED No contact means you now do two things. You wear the bit MALE flanges and you STRIP the FEMALE indentation flanges. The steel in the screw is much much softer on a common Phillips screw than the bit. The bit is TEMPERED. Much harder steel. Deck screws, Sheetrock screws, machine screws etc are a different alloy, and are less prone to stripping. But then, they DULL the flanges on the driver bit. VOILA! Now you have a dull bit, and a screw half flushed and you can't drive it any further. SHIT. You know either remove it with the bit. It MIGHT WORK but if not, then proceeds to dull the bit in the OPPOSITE direction and strip the screw too.
The next screw you use, NOW will NOT fit correctly. You now have a better chance at striping it as well as dulling the bit even further. Or you use a pair of pliers to back it out, or with harder screws, you knock the head off with a hammer. Or cut it off with dykes or a hacksaw
Solution #2 Use a magnetic driver to hold replacable bits. Buy 5 or 6 replacable phillips bits at the counter. They usually have a JAR of them or some kind of display with Phillips bits by the bulk. (are we spoiled or what!) If you dull one in one whack, REPLACE IT. Now some of you may think I'm crazy, but I build all the time. These are POINTERS only.
Solution #3 Use pilot holes. When you are fastening something to wood with a screw, the threads are what pull the head closer to the surface. IF you are fastening something to wood that has NO HOLE to place the screw through, the threads have to bite into it first. Imagine this. Think of a washer. I use them all the time(more of that in the next installment!Ha!) A washer has a hole. It does two things. First it allows the screw to FREEFLOAT in the hole, and second, compress whatever is below it, as the screw embeds into the SECONDARY surface and pulls up tight. The first surface is the PRIMARY surface, which is the face of the washer that is facing the underside of the screwhead. It could be anything. Another piece of wood, a metal flange, hardware, plastic etc. But imagine its not a washer, but another piece of wood. IF there is no hole through the PRIMARY surface material, then you must either, DRIVE the screw through it or drill a hole large enough for the screw to FREEFLOAT. IF you chose to drive the screw, two things happen. As soon as the threads BITE the primary surface, torque is applied to the item. If you are holding it, say a short piece, it wants to rotate with the screw. BAD NEWS. YOU CAN GET HURT. ESPECIALLY will SHEETmetal. NEVER try to hold a piece of metal with one hand and ENLARGE a previously drill hole to a size larger than 1/4" with the other. Even smaller although its less torque and smaller teeth. Even with variable speed drills(more on them later). A large drill bit will bite into a smaller hole, but if that hole is too small the bit bites, but WILL NOT CUT. The torgue is IMMEDIATLY transmitted to the metal, and can pull from your grip. One revolution of the drill, on a piece 6" long can wreak havoc on your fingers in a BLINK of an eye. Same with anything with no PILOT hole and a screw.
If possible, always drill a PILOT hole THROUGH the primary material. This hole should be a fraction bigger than the screw you are driving so it will FREEFLOAT. Now, place the primary material where needed, insert a screw, and place the bit into its indentation, PUSH to engage the threads into the secondary surface, and start the drill. Keep pushing, but use as much pressure and slow as speed as you need to keep the bit from SLIPPING. OK. Another reason for a pilot hole. IF you manage to drive the screw through the primary material, and it is in position to drive the screw right on into the secondary surface, this is what happens. As the threads touch the secondary surface they do NOT immediatly grab. As the screw rotates, it is now pulled further out of the rear face of the primary material. The longer it takes to grab, the GREATER the distance from the primary rear face to the secondary face will remain when the screw head reaches the primary surface. VOILA! A gap between the two materials. And no matter how hard you try to pull that gap up, the more it wants to strip the screw. Because it can go no deeper into the primary surface. Hmmmm! UNLESS, the primary material is SOFTER than the secondary material. IT MAY strip the primary material away from the threads, which actually creates what you should have done in the first place. A PILOT HOLE
....OR.. Clamp the two materials togeather. Then they act as one piece, like with two pieces of ply, or 2x2's or 2 x anything. Usually you can drive a screw through two layers of 2x if they are held down tight, or clamped or have enough weight to keep the screw driving immedietly through the secondary surface. BUT IN THE CASE OF HARDWOODS, PARTICLE BOARD, MDF, MELIMINE, HARDBOARD, MASONITE, PLEXIGLASS, METAL GLASS, ALUMINUM ETC. ETC. YOU MUST drill a pilot hole. This is why. 2x material such as FIR, HEM FIR, PINE, ALDER, PHILLIPINE MAHOG and other softwoods such as fir ply have fibers which will COMPRESS and TEAROUT. They allow a screw to penetrate easily. The other materials on the other hand will NOT as they either have small fibers and composition whereby the screw shank can not compress the material it is replacing as well, or will not compress it AT ALL, such as plex and metals. These materials must be addressed in a different manner. This is a guidelineIF, the primary surface is a hard material it must have a pilot hole.
If, the primary surface is a softer material than the secondary, you may get away with driving it directly through it into the secondary material. PINE, SHEETROCK, PLYWOOD, 2x fir etc are examples you can drive a screw through
IF the secondary surface is SOFT you can drive the screw directly into the material.
IF the secondary material is HARD you MUST drill a SECONDARY pilot hole. This hole should equal or be a bit larger than the SHANK of the screw, but LESS than the threads. In hardwoods you can fudge and the hole can be slightly smaller than the shank due to minute compression. In that case dip the screw in wax. Ha!
IF the secondary is Particle board it will penetrate with no secondary pilot hole, due to large fibers and the bonding material will compress with it. It will however result in the compressed material LIFTING a dimple of material around the screw shank. IF the primary material is hard, it will also compress this dimple and allow the sufaces to pull up tight. If it is softer, then the dimple will penetrate the primary material. That is assuming you drive the screw to its maximum torque, which is when the screwhead makes contact with the primary surface and the screw will no longer turn. In the case of Phillips screws, this is where an Amateur ruins his first phillips bit. As the head comes to an abrubt halt, because the amateur is not PUSHING hard enough, OR is using MAXIMUM speed on the drill, the momentum of the drill armature, is such that it DOES NOT stop rotating. The bit lifts out, keeps rotating and VOILA! Dull driver. Stripped screw. And the scenario keeps getting worse with each time this happens. But to make matters worse, IF the screw is soft you may pop the screwhead off from pushing TOO hard and TOO fast. See it all the time. This also creates another scenario.
As the head comes in contact with the primary surface, either it will penetrate to the point of self countersinking into the surface(soft materials), or will stop at the point of where the underside of the head, which is tapered, contacts the edge of the pilot hole or selfmade hole and comes to a sudden stop. OR POP! Depending on the above conditions. If it stops, the flat screw head will be above the primary surface. In the case of softwoods, as it countersinks into the material, it too creates a small raised donut of material around the screw. And worse in softwoods, the screw will pull through so fast that a donut forms but then pulls into the hole over the screw head. Which is ok if you never have to remove the screw. If you do that in laminate, when you remove the screw, it now will lift the laminate and break out a large chunk, THEREFORE, the pilot hole should ALSO include a COUNTERSINK. It is not required by anything other than more pulling power is applied as the full surface area of the tapered surfaces of the countersink and screw head(underside) come in contact, flush screw aesthetics, or another surface being fastened over it. Also you can drill the countersink deeper, and place a plug, or cover or putty etc. into it. Ok, you still with me? Ha! Were not done yet.
MDF has other considerations. As a primary surface, you must drill a pilot hole. A counter sink is optional. Depending on you. If the screw is driving into hardwoods as a secondary material, it will countersink itself, but with a LARGE donut. This is because MDF is primarily EPOXY, which is hard. The wood is dust, added for filler. There is nothing to compress. If you drive a screw through a piece of 3/4" MDF, with no pilot hole, the thickness of the panel will increase to compensate for the expansion caused by the shank replacement of material equal to the mass of the replacement. It has to go somewhere. What it does is fracture the bonds between the expoxy and wood dust equal to the screw mass, and spreads this expansion equally through the panel around the screw. It will also form a donut at the point of the screws entry and exit. As I said before. If your fastening something hard or small to it as a (MDF primary material) doesn't matter, as a certain portion will force the thickness to increase on the opposite face of the+ panel. If you then drive the screw on through to a HARDER material, it will recompress the fractures, but then the head may countersink or pop the head. If it is a secondary, you SHOULD use a secondary pilot hole. Especially if the MDF panel is thicker than 3/4. " Usually a screw can be driven all the way through the rear face unless other conditions do not allow it. In that case, the screw only has 3/4" to bite. Panels thicker such as 1 1/2" will bring the screw to a halt before it is fully driven With no secondary pilot, the screw will fracture the bonds, and now the threads have a limited ability to do their intended job, and may even tear out. VOILA!, no holding power. Or, break the screw. Now, MDF edges being used as a secondary surface have one more issue. If you drive a screw into the edge of MDF, you may get away with it if your only going in 3/4". But since the bonds are the weakest at the edge, any deeper than the thickness of the panel will now force the panel to fracture at its weekest point and the panel will split. Now your fucked. Therefore, DRILL A SECONDARY PILOT HOLE DEEPER and use longer screws, Usually, 1 1/2" into an edge.
Solution #5 Buy a set of countersink, primary pilot cutter, drill bits. Usually you only need 2 sizes. #8 and #10. Great if you have a bunch of holes to do, which is not uncommon for panel/fixture/cabinet work. Even in 1/4" masonite. You must drill and countersink. Same with plastics(laminates), plex(requires a special drill bit for large holes) These will drill a primary pilot and countersink into the primary material, and a secondary pilot(smaller) into the secondary material when positioned prior to drilling.
Solution #6
Ok! IF YOU DO manage to find the SQUARE HEAD RECESS screws buy what ever you want to spend. They are usually IN BULK. Say, 1/2 pound each of the smallest(1" probably) up to 3". Cost maybe $10. Be the best $10 you've spent in a while, especially if your a DIY like me, or your a homeowner and build/repair a lot.This is why.
First, SHR screws have 3 things normal Phillips do not have. One is the square recess. It does not allow the bit to slip, unless you do not push. But you don't have to push hard unless the material is hard too! Just push hard enough to keep the bit engaged as it drives into the material. Let the threads do the work.
Second, most shr screws have whats known as "GRABBER" threads. Phillip screws are available with these and are actually called GRABBERS. Thats because the thread goes all the way to the tip of the screw so it IMMEDIATTLY grabs. All the way through.
Third, some shr screws have self countersinking teeth on the underside of the head.
Well, shit, theres my book for the week. Hope this enlightens you to some DIY help in "fastenening" skills. To me, fastenening things togeather is the heart of building. Theres a million ways, techniques, hardware, and processes. I'll post more here as time goes by.
fitz
knightfly
GrouchyOldFartOnBatteries
Damn, fitz - now I KNOW you're a screw-up :=)
Butt Seriously, there's only a couple things I could add to that -
one, My eyeballs nearly fell out trying to keep track without paragraph breaks -
and, (b) If you're REALLY serious I recommend (and use) a separate screw gun that has both torque and depth stop capabilities, and a keyless chuck drill with whatever drill/pilot I'm using -
I gave up on battery powered drills for anything serious - for the cost of the extra batteries you need to keep going, you can buy 2 or 3 more power tools.
If I'm using a straight bit instead of a combo pilot with built-in stop, I always add a stop collar to control depth.
I also keep a compressed air blow gun handy, and if I drill a few dozen pilot holes at a time I'll pass over each of them with the blow gun to make sure the holes are clear.
If you're gluing AND screwing a wood project (and you normally should) you can NEVER have enough clamps of various size and type - I try to buy a few every month, since they are FAR from free...
OK, that was more than two - so sue me... Steve
Butt Seriously, there's only a couple things I could add to that -
one, My eyeballs nearly fell out trying to keep track without paragraph breaks -
and, (b) If you're REALLY serious I recommend (and use) a separate screw gun that has both torque and depth stop capabilities, and a keyless chuck drill with whatever drill/pilot I'm using -
I gave up on battery powered drills for anything serious - for the cost of the extra batteries you need to keep going, you can buy 2 or 3 more power tools.
If I'm using a straight bit instead of a combo pilot with built-in stop, I always add a stop collar to control depth.
I also keep a compressed air blow gun handy, and if I drill a few dozen pilot holes at a time I'll pass over each of them with the blow gun to make sure the holes are clear.
If you're gluing AND screwing a wood project (and you normally should) you can NEVER have enough clamps of various size and type - I try to buy a few every month, since they are FAR from free...
OK, that was more than two - so sue me... Steve
RICK FITZPATRICK
New member
Hi Steve, sorry bout the paragraphs. And the long wind. But I figure if they ask, then I have my 2cents. But it turns into $1. And thanks for the adds. Figured my mouth had been open long enough
fitz
fitz
RICK FITZPATRICK
New member
Hey Steve, I 'PRECIATE it man. Anything from YOU makes my day.
BTW, I've seen a lot of accidents at work. EVERY SINGLE ONE is operator error!!
And some of these guys been around along time. Usually its from rushing. Saw a guy use a nailer with his right hand and holding something undernieth the panel with his left. Drove a 2" finish nail right up his finger. DUH! No sympathy here. But I've been just as careless. I've got the scars to prove it. What a moron
fitz
BTW, I've seen a lot of accidents at work. EVERY SINGLE ONE is operator error!!
And some of these guys been around along time. Usually its from rushing. Saw a guy use a nailer with his right hand and holding something undernieth the panel with his left. Drove a 2" finish nail right up his finger. DUH! No sympathy here.
But I've been just as careless. I've got the scars to prove it. What a moron fitz
knightfly
GrouchyOldFartOnBatteries
Drilled a small hole in my watch (wearing it inside wrist) once, holding a piece of 1x2 steel rectangular tubing with left arm behind it and drilling a pilot hole with the right - good thing it was a cheap timex - it may have been dead before the drill bit hit it, the whole front was shattered by the "squeeze" I put on it.
Didn't try that one again, once was 'nuff... Steve
Didn't try that one again, once was 'nuff... Steve