# this to that . com



## ship (Feb 5, 2007)

So in a pinch or how sufficiently & with what special details on doing so:

Will a latex based caulk - glue (sufficiently that it won't easily pull apart,) a expanded polystyrine sheet such as blue or pink dow board to say CDX grade plywood? 

How about it gluing expanded (white foam) polystyrine to the plywood?


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## Van (Feb 5, 2007)

Well Here's the deal. While Latex ccaulk is an excellent adhesive to use on the outside of polystyrene, it is a lousy glue for use as a bonding agent between layers of foam. This is one of those I found out through expirience. The problem is that as soon as the outside area of latex sets up it seals the interior area from exposure to the air, thus sealing the caulk on the inside just as if it were in a tube. If you allow a lot of tack time and use thin layers it might work, but iwould recommend either using a latex based cove base adhesive, or if you can find the brand name "30 Neutral" use it. 30 Neutral is a latex based contact cement. You coat the foam let it set up then stick it together. 30 N also works well for glueing wood to foam. You cannot use a standard contact adhesive on polystyrene foam as it will eat right through it. same goes for most spray glues, although 3m does manufacture a spray foam adhesive that works real well on thinner foams but it doesn't have the void filling capabilities that a contact adhesive does.

So short answer: 
Polystyrene to wood = 30 Neutral, Latex cove base adhesive, or a foam safe "liquid nails" the regular stuff eats foam.

Polystyrene to polystyrene= 30 neutral, latex cove base adhesive,foam safe liquid nails.

stay away from goriila glue, or any other type of polyurethane glue they expand as they cure, they require hydration to set which is sort of counter-intuitive when working with foam. 

stay away from any bonding agent that has a lacquer thinner, acetone or similar smell to it ie regular liquid nails.


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## Footer (Feb 5, 2007)

I can't remember the 3m number, but what I call Green Glue works pretty amazingly for foam to foam and foam to wood gluing jobs.


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## ship (Feb 6, 2007)

Good start, but intended to be a this to that type of theory type of thing. So if I'm correct with the above answers, latex caulk while not optimum should work if it's dispersed properly correct? Well thought out responses - in theory it could work... sufficiently.

How about silicone based caulk in a similar way?



Next question in a similar way to the above, how about latex paint verses various forms of oil based paint as a glue by way of the binders in the paint between layers of the plywood and foam? Could two layers of paint - various types work sufficiently as say a glue or contact cement? 

How about rubber cement?

This is intended to become a sort of theoretical type post - give your thoughts on the question and challenge the others to another "this to that" type question. Doesn't have to be foam to plywood, could be burlap to say felt or any type of lamination question. Sort of a mind tease that's hopefully active and curious. This beyond or including the well troden posts about the abilities of say liquid nails to stick or not stick to foam dependant upon what lot number it is. More get into the theoretical side where possible... say beer or soda as a better paint thinner type concept.

Something like along with Gorilla Glue, there is a new style of gel super glue out there. How well will it bond nylon say as a nylon end termination to the wire rope push/pull mechanism of a trunk/gas cover reliese in all forms of temperature and dampness but definate tension/compression stress to the joint? Say the nylon piece broke in half. 

Or say compare and contrast question Gorilla Glue verses gel super glue for the above applications. 

Than of course if wished such as the above green glue or foam panel adhesive or blue contact cement... products that would more properly do the task one could mention. Not so much as a better solution as if the questioner were asking how to do it best, but more as a side note on what's really recommended.

By the way, the above website is very useful.


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## ship (Feb 6, 2007)

Footer4321 said:


> I can't remember the 3m number, but what I call Green Glue works pretty amazingly for foam to foam and foam to wood gluing jobs.



#74 foam fast works well, but it's in an orange color coded can. How about in bonding #74 or #99, given both of these are spary based and not roll on as advised.


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