# Will "real" contact cement work over failed non-flammable?



## bunburryist (Oct 1, 2011)

I made the mistake of taking the advice of the "expert" at Home Depot and used the Weldwood "green can" non-flammable contact cement to glue Formica to hardwood plywood. It didn't hold at all. (From what I've since read in reviews of this product, I'm not the first person with this problem. What I'm wondering is if, after letting this JUNK completely dry, I can use "real" contact cement over it. I already have two coats of the non-toxic crap on the plywood and one coat on the back of the Formica. Adding another coat each to the wood and Formica, it would be 5 coats of contact cement all together. I really don't want to have to start from scratch - making the counter-top all over, ordering the Formica all over - not to mention all the money. Do you think this can be salvaged, or am I better off just calling it (the world AND money) a loss and starting all over from scratch?


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## BigJim (Sep 2, 2008)

I have done tons of "Formica" work (that is actually a brand name) I don't see a problem to use the solvent contact over the water base because once the water based is completely dry all you will have is contact anyway. You do know how to do the solvent contact don't you? Here is a link to some instructions if you need them.
http://www.diychatroom.com/f98/how-build-laminate-countertop-166320/

Just a question on the water base contact cement, did you stir it up really well or just use it without stirring? If you didn't stir it well, that may be your problem. Another thing is if it is raining and the humidity is really high that could be a problem also. Water based contact is not as easy to use as the solvent contact, but it does work. 

Just another thought, if you let the contact dry too long before sticking it, it won't stick either.


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## bunburryist (Oct 1, 2011)

Jim - Thanks for the ideas. I did it exactly like the directions you linked me to said. It is humid, so maybe that's it, or maybe I waited too long. Parts of it did stick, but parts didn't. I waited about 45 minutes. The can says that if you wait "two or three hours" you need to put more on to reactivate it, so I didn't feel like I needed to be in any rush. I've used the "little brown bottles" of contact cement for all kinds of things, but this stuff was completely different so that I didn't really know how it would act. I noticed it wasn't sticking when I tried to put the first of two panels on, and when I took it off the cement on both the panel and the plywood was "messed up." We managed to rub the cement off of the panel, but the plywood is messed up, so I think I'll go ahead and make a new piece. It'll cost a little, and take a few hours, but I'd rather have a clean piece. I don't see how I can get the plywood smooth enough that it won't show in the end. The second panel is undisturbed. In order to try and keep the thickness even I'm going to put two applications on the panel we peeled the cement off of. I've seen a lot of negative comment posts at various places on the stuff I used. I wonder if it really is that bad (in which case you'd think they'd take it off of the market), or maybe it's just that it's the people who aren't happy that post comments! Thanks for your response.


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## bunburryist (Oct 1, 2011)

One more thing - how long do you think it will take to be dry enough to put new cement over?


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## BigJim (Sep 2, 2008)

If you can touch it now and it doesn't come off on your fingers it will be ok to go ahead and reapply the cement. If you waited 45 minutes you did wait too long. As warm as it is here in Tennessee right now 15-20 minutes is long enough for solvent cement to dry and not much longer for water base. 

You might try putting lacquer thinner on the plywood and use a scrapper to get the glue off. If it is smooth it should be ok.


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## user1007 (Sep 23, 2009)

Are you using something like a laminate roller to make sure you have solid contact?

If this was a box store purchase is there a chance the adhesive was beyond its expiration date? I cannot tell you how often I have followed behind DIYers that did everything right but check the expiration date of adhesives, two-part epoxies and so forth. I guess the employees get lazy and hide the old stuff rather than cart it off or something.


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## bunburryist (Oct 1, 2011)

I went with Big Jim's advice and stripped the cement off of the plywood. It took about four hours, but it came off. Next time (there won't BE a next time - no more non-toxic/flammable for me!) I'll use something stronger than thinner. It did all come off, and the counter top came out perfect. It was worth all the trouble. (I did have a short, minor heart attack, though. I had just finished the first quart of "real" contact cement - same company, but real stuff. When I opened the second can it looked, well, all curdled! My heart just about fell out of my chest! NOT AGAIN! Then I looked at the can - it was the paste version (or something like that). The cans were virtually identical! I called the manufacturer and they said it was essentially the same stuff, only a different texture. WHEW! It ended up fine in the end. Thanks for all the help. Rob


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