Hello All,
I am rehabbing a pair of bookshelf speakers from the late 70s. They are typical particle board construction of the period. Strictly as a prophylactic measure, I want to seal all interior seams (any adhesive property would be acceptable too)
I'm looking for recommendations for a sealant/adhesive which will not adversely affect x-over components. Silicone is obviously out (as is neutral cure silicone) as neither bonds well to particle board. I see a number of ultra-low VOC formulations on the green building sites, but don't know if this aspect alone ensures compatibility with electronics.
Thanks in advance for any suggestions.
I am rehabbing a pair of bookshelf speakers from the late 70s. They are typical particle board construction of the period. Strictly as a prophylactic measure, I want to seal all interior seams (any adhesive property would be acceptable too)
I'm looking for recommendations for a sealant/adhesive which will not adversely affect x-over components. Silicone is obviously out (as is neutral cure silicone) as neither bonds well to particle board. I see a number of ultra-low VOC formulations on the green building sites, but don't know if this aspect alone ensures compatibility with electronics.
Thanks in advance for any suggestions.
EVERBUILD® BLACK JACK® 908 D.P.M. | Bitumen & Roofing Products
Don't know if you can get that where you are but there is probably something very similar. It is water-based rubber enriched bitumen paint. It seals and you can use it as an adhesive too including styrofoam. Smells a bit like tar when you apply it but that goes away once dry. I coat the inside of all my speakers with this and use it to fix damping foam to the inside walls.
Don't know if you can get that where you are but there is probably something very similar. It is water-based rubber enriched bitumen paint. It seals and you can use it as an adhesive too including styrofoam. Smells a bit like tar when you apply it but that goes away once dry. I coat the inside of all my speakers with this and use it to fix damping foam to the inside walls.
Thanks Charles - we definitely have the Sika brand here in the 'States - but not sure about this particular product.
Recently I got a pair of speakers where walls had started to separate because of them being stored in a damp place. I used epoxy resin to seal all seams from the inside. It is stronger than ever before now and epoxy is odorless ond non aggressive, neutral when cured. I just mixed a small amount, put it inside and let it reach any corner of the cabinet by turning it around serveral times.
Liquid Nails AS825 acoustical sealant? I've used a number of their products, mainly the construction adhesive which I believe would work just fine in this case but this may be better
You could think of using foam board and build new housings.
It is much more stable and durable than particle board.
Particle board can be protected with sealants like construction adhesives, and also polyurethane based wood finishes.
You could even try the underbody coats sold for cars, there are many choices, but how well they adhere to wood needs to be checked.
Coal tar will crack after some years due to heat cycling, a flexible tar substitute may be a better idea.
It is much more stable and durable than particle board.
Particle board can be protected with sealants like construction adhesives, and also polyurethane based wood finishes.
You could even try the underbody coats sold for cars, there are many choices, but how well they adhere to wood needs to be checked.
Coal tar will crack after some years due to heat cycling, a flexible tar substitute may be a better idea.
Absolutely
But the wiser course of action is to treat them while they're apart for x-over upgrades.
This method not only strengthens the (half-century-old) glue joints, but seals any possible cabinet leaks -- the latter of which may well pay sonic dividends!
PVA can be weakened by moisture in humid conditions.
Wood glue, the white kind, is usually PVA emulsion, with water as a major ingredient.
Should not be a problem if properly cured after application, but not worth the risk with porous stuff like particle board, in humid conditions...repair will be a headache.
SBL, a water proofing sealant, is a better option, you can water proot by painting (on a prepared dry surface) swimming pool walls.
Use it without dilution, after stir / shake, on a roughened clean dry surface.
YMMV, try on a scrap piece first.
Wood glue, the white kind, is usually PVA emulsion, with water as a major ingredient.
Should not be a problem if properly cured after application, but not worth the risk with porous stuff like particle board, in humid conditions...repair will be a headache.
SBL, a water proofing sealant, is a better option, you can water proot by painting (on a prepared dry surface) swimming pool walls.
Use it without dilution, after stir / shake, on a roughened clean dry surface.
YMMV, try on a scrap piece first.
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Interesting that you would write that -- after (possibly far too) much research, I have settled on the following:
Chem Link M-1 Structural Adhesive Sealant
If you only want to seal it air tight and follow instructions, this should be OK. Anyway, I would not use this stuff on a speaker cabinet old or new. It does not fix a failing bond between panels. Once you open the container it will cure by it self in a few weeks, so it is expensive and most of it waste; something that is common with all these wonderfull modern expensive 1-component stuff. For lose panels that let air through, you need something that seeps away into the material, like a low viscosity resin. Even simple PVA glue would work better, while a two component substance has the advantage of 100% curing after the time mentioned in the instructions when both components get mixed. That is why I would use Epoxy. Also, epoxy components don't cure by them selfes, you can use them for years if keept close. You can even liquify it once cristalized, by heating it up for 10 minutes or so. I have industrial epoxy that is 20 years old and still useable. Epoxy resin can be filled with wood dust, sand or any fiber, colored etc. So you got a whole lot of different options in a small pair of bottles. And boy, that stuff sticks like nothing else. You can heat cure it for shorter curing and even better joint quality.
Chemistik M-1 is polyether, a different chemistry.
SBL is quite cheap, and sold by many sellers, who get it in bulk.
Here it is about $2.50 for a half litre, $20 or so for 5 liters.
You need at most a quarter liter for two coats on small speakers, and it stays liquid in the bottle for two years if stored tightly closed.
SBL is quite cheap, and sold by many sellers, who get it in bulk.
Here it is about $2.50 for a half litre, $20 or so for 5 liters.
You need at most a quarter liter for two coats on small speakers, and it stays liquid in the bottle for two years if stored tightly closed.
Make no mistake -- I truly appreciate your input, but there is no problem with the current integrity of these cabinets. As I stated, this is strictly a "prophylactic" or preventative measure, taken because the cabinets are empty due to a crossover upgrade.
If there is no fear of the wood panels comming loose, there is no need for "prophylactic" measures. Instead of using some swimming pool sealer you could just run some wood glue over the edges or apply it with a brush. PVA = wood glue is made to glue wood and used for it because it works just fine.
I don't understand why one should use something made for a very different task and with a totaly different adhesive system on wood. Wood glue, like epoxy, connects the wood fibers by penetrating, while pool sealer is made to stick on the surface and can be peeled off easily. Makes no sense to me.
Good luck.
I don't understand why one should use something made for a very different task and with a totaly different adhesive system on wood. Wood glue, like epoxy, connects the wood fibers by penetrating, while pool sealer is made to stick on the surface and can be peeled off easily. Makes no sense to me.
Good luck.