acoustical caulk?

[halfguard]

is acoustical caulk worth it? does it make a difference or is it the same thing? thanx for any help.............

 

[SonicClang]

Wha? Allz you need is silicone-based calk that stays pliable after drying. The caulk is just used to seal things up, there isn't anything magical going on that would require any "special" stuff.

 

[knightfly]

Sonic, caulking a studio isn't quite as simple as that; from all the literature I've read and people I've dealt with on this, about the ONLY "normal" caulk that won't either shrink or dry out and crack (NOT what we want) is GE's Silicone II, which costs as much at home depot type stores for a 10 oz tube as the REAL acoustic-rated caulk does for a 29 oz tube. In actual use, this becomes a 3:1 difference in cost - enough in most cases to buy a decent compressor or another guitar processor...

Properties of acoustic rated caulks are less/no shrinkage, heavier weight (less isolation loss where the caulk is, compared to wallboard) -

Also, very few acoustic caulks are even offered in the smaller tubes so you save on packaging.

Whichever caulk you use, foam backer rod should ALWAYS be used before caulking - here's why

http://www.johnlsayers.com/phpBB2/download.php?id=6542

http://www.johnlsayers.com/phpBB2/download.php?id=6541

Problems that can show up (if the above are NOT followed) after a few months or a year or two are cracks in the caulk beads that will lessen LF isolation.

When the "fix" requires removing entire wall sections to get at the bad seals (assuming you can even FIND them) it gets kinda painful... Steve

 

[Bill Furnett]

Questions please:

1. Is the foam backer rod something available at like a Home Depot?

2. Anyone have a pic of it?

3. Is there a common subsitute of the same material such as the formed pipe insulating foam?

4. Is there anykind of known chemical reaction between regular silicone based caulk and foams that A: Is toxic? B: Causes foam to break down?

Thanks

 

[knightfly]

http://www.loghelp.com/backerod.html

HD doesn't seem to wanna sell it by any name I'm familiar with, although I think I've seen it there.

reactions; not that I'm aware of; this is what the stuff is for, so just about any kind of caulk should be OK. Still, for sound applications you should be using one or another of the acoustic rated caulks; as I said, they cost about 1/3 as much per foot of bead as the only NON-acoustic brand I've known to work, so it only makes sense to save a couple hundred bucks using the real deal... Steve

 

[RICK FITZPATRICK]

Hey Steve, I've often wondered about the "bond" when caulking to gypsum(edge of drywall) Ever read anything in that regard? It would seem to be weak due to the physical nature of gypsum(chalks?). Especially if I cut it.

 

[knightfly]

Yeah, it can be; all the more reason for the backer rod, so one of the IMPORTANT bonds doesn't get pulled loose with things shifting. (explained in the two previous links) - Also helps to be a bit forceful when caulking (squeeze a lot, move slow) so the caulk gets pressed into the drywall edge firmly... Steve

 

[Notfonts]

I used Sashco Big Stretch, it doesn't harden, water based, smells ok and a lot cheaper than acoustical caulk.

http://www.sashcosealants.com/home_improvement/products/bigstretch.shtml

 

[Bill Furnett]

When i asked after reaction to foam i kind of meant reg caulk and like pipe foam. I just didn't want to experiment and create Fumeinstein, but with the Big Stretch available a mile away from me that won't be a problem.

Thanks to all for the insight as i was just days away from a waste of time and effort (not to mention extremly frustrating) F up.

 

[knightfly]

http://www.sashcosealants.com/home_improvement/pdffiles/bigstretch_brochure.pdf

Finally found it under Packaging - these are 10 oz cartridges for $5.50 per cart; you can get actual acoustic caulks for less than that for THREE TIMES AS MUCH CAULK - doesn't sound like much of a bargain to me, but it's your money... Steve

 

[Bill Furnett]

Chicago man succombs to caulk purchasing considerations, film at 11

Ok, what is the brand name of the actual accoustic caulk that is a better deal and who sells it please?

 

[SonicClang]

considering it's taken me 6 years to build my studio, I've actually had some real time to look at some caulking I did years ago, and all the silicone-based caulk is still performing to this day. At times we used cheaper stuff and some of that has cracked. It's about twice as much for slicone-based caulk, which is why we tried the less expensive stuff. It too me a long time to get everything closed up. Most people get their studios done quickly and never have a real opportunity to observe the caulk once it has dried.

 

[knightfly]

http://www.whitecapdirect.com/store...603025012&destination=/store/product-v2.0.jsp

Even this is a better deal than the sashco -

http://www.acousticalsolutions.com/products/sealants/caulk.asp

Other than that, locally you can ask about OSI-175, USG acoustic caulk - try drywall supply houses and commercial supply places, HD won't have it... Steve

 

[Bill Furnett]

Again thanks Steve

After reading a bit and taking into consideration the expansion and contraction from season to season in my A-frame attic in Chicago's climate plied with the amount of sound pressure expected to be generated in the small booth spaces i'm building, a lot of light has been shed on what would have been an otherwise overlooked but now obviously critical factor in achieving the best seal possible. I'm happy to report there's a Whitecap here that i've gone past a million times.