Contact Cement Failures. HELP!!!

[Nick Sorenson]

I'm using DAP Weldwood contact cement (the original flammable stuff that will make you dizzy) to glue some Formica laminate to pine (lining a storm window sill).

Here's what I'm doing:
I'm coating the wood and letting it dry 10 minutes. The wood proceeds to drink this up and leaves a dry slick surface as if I did nothing.
I add a 2nd and 3rd coat just like the first. I also now add a coat to the laminate. Now the wood looks sealed and after 5 minutes feels tacky. All seems well so I then proceed to stick the laminate to the wood.

After a day, it pops loose in several spots. I can re-press it and it'll stay for a second then comes loose again.

Any ideas on what could be wrong?

https://mobileimages.lowes.com/product/converted/070798/070798002739.jpg?size=pdhi

[Mel Fulks]

I don’t see your location noted. But the stuff doesn’t work well in the cold , and really isn’t a permanent type adhesive. Inside it usually
lasts until your interior decorator tells you to get rid of it.

[Nick Sorenson]

I don’t see your location noted. But the stuff doesn’t work well in the cold , and really isn’t a permanent type adhesive. Inside it usually
lasts until your interior decorator tells you to get rid of it.

It's in the 50s in Missouri recently. Isn't this stuff used for counter tops?

[Mel Fulks]

Too cold , I think you need at least 70. But please read the directions.

[Austin Perera]

I’ve used that to laminate Formica to plywood for an aquarium cabinet. Following the directions, the bond was definitely permanent and even after 8 years would be impossible to remove. I suspect it may be a combination of temperature along with the pine soaking it up. When I did it both the plywood and the Formica had a film on them that held really tightly when pressed together and once pressed together you couldn’t pull it back up even if you wanted to adjust it. You may need to first seal the pine so you can get that tacky film surface, but I’ll wait for others to suggest what to use. Are you also waiting long enough for the surfaces to become dry before pressing them together? If I recall it needed more than 5 minutes.

[Si Wood]

I have used both solvent based ( as in this one ) and water based and have done a LOT of laminating but on particle board for store fixtures and counter tops. I have never laminated pine but I can take a stab at your issue. Pine has a lot of natural resins some you can see on the surface but at times, depending on the board, there could be resin " pockets " below the surface. You will also see resin, some call it pitch around knots. I'm only guessing but the fact that the contact cement is solvent based is possibly diluting the resins in the board preventing adhesion.

[Bruce Wrenn]

Neither piece should feel "tacky." It needs more time. If everything else fails, read the directions. Also are you applying enough pressure to make the bond?

[Vince Shriver]

Years ago I worked in a cabinet shop that made fixtures for beauty shops, and about 90 percent of what we made was with plastic laminate. The above advice is right on. Contact cement needs a warm environment. Also, I think you need a longer open time - maybe 45 minutes or so before sticking the laminate to the sub straight.



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[Frank Pratt]

What Bruce said. If it's still tacky, it's not dry enough. The glue should feel completely dry to a light touch. in dealing with the differing surfaces, you should put an initial coat on the wood, let it dry, then apply a coat to both surfaces. More coats will give a weaker bond as well as an unsightly, thick glue line at the edges. I've never applied more than 2 coats.

[Lee Schierer]

The instructions (https://www.buildsite.com/pdf/dap/DAP-WELDWOOD-Original-Contact-Cement-Product-Data-1875954.pdf) say to wait 15 minutes before applying additional coatings of cement. I suspect that Bruce is correct that the cement you applied wasn't dry long enough to produce a good bond. You had about 2 hours of open time to work with after the final coating. Tacky surfaces shouldn't be placed together. If adhesive comes off on your finger when you press against it it is still too wet to bond.

[Dan Gaylin]

Agree with previous comments. Either too cold and/or you didn’t wait long enough and/or you had a bad can. I have had a bad can of this stuff. It doesn’t turn over on store shelves as rapidly as some products.

To use it successfully I often wait 30-40 minutes in a warm dry environment before sticking the pieces together.

[Kurt Cady]

Are you just sticking it on or rolling it hard with a J-roller

[Tom M King]

You're not letting it dry enough. "Tacky" is still too wet.

[Nick Sorenson]

Excellent and thanks. I had read on the can that a knuckle should come off dry but a little sticky (at least I thought it said a little tacky I'll read it again). I watched several videos that show it as almost dry before sticking.

I think temp and humidity were part of my problem. I'm lining the inside of a storm window and there was both cold and humidity taking effect by the end of the day. The earlier work did hold up better. Maybe summer time full heat on a dry week is a better bet. I will practice a little more on scrap.

thanks again for the tips!!

[johnny means]

+1 on the dry not tacky advise. You want it completely gassed off before sticking. Remember, it's not glue. It's more akin to making masking tape. You wouldn't expect tape to stick to a wetted surface. Temperature and humidity shouldn't really cause an issue as long as we're not talking extremes.

[Richard Coers]

+1 on the pressure. In junior high school shop class, a block of wood and a hammer was used instead of a J-roller. Made me think the contact meant contact with a hammer and wood block! But really it is just a way to make full contact between both surfaces that you won't get just by placing the laminate on the wood.

[Gordon Stump]

That stuff is a permanent bond. Properly bonded surfaces can only be released by spraying acetone in a toe hold and working it apart. Swearing, screaming and whining is warranted. I have worked with way too much laminate. :rolleyes: So the cooler the surfaces the longer to open time. No glue should release when pressing firmly with your finger. Not tacky. Some laminates also soak the glue so I would often apply a second coat to that a well as the sub-strait.

Best of luck.

[Warren Lake]

operator error. Once done it stays, have done the time to prove that. If stuff need to be changed later years just put it on its side, open an edge with a chisel and use Lac reducer in a squirt bottle. It will pool in what is pulled away from the substrate and do work to your advantage and keep loosening. Simple. Worked lots of it and 40 years later its same as it was when made. Last fav brand was Nevamar, model of it I used the most was bullet proof. Sure there are tons of choices now.

[Mel Fulks]

This thread has inspired me to look up new views on contact cement. Don’t see as much about failures as I used to. The on the phone reps
used to say that it “would last 5 to 10 years”. Maybe it’s better now than it was then. One company I worked for would
only use plastic resin glue for laminates. Many times I’ve seen contact cement fail before it left the shop. That never brought any re-evaluating of its merit ,only a some cussing and more contact cement.

[Warren Lake]

HI Mel

dont want to disagree with you considering your history but if so then you had some morons working there Im sitting at 35 years at the moment. Failures in contact are more associated with veneer applications.

The best shops in Toronto did put it on in a press with different wood glues, if they did banks and stuff the laminate was worn out from customer friction before it ever failed. Ill email the top glue pro I know, about your 5 -10 year thing, Ive proven him wrong 3 times his high number. There were good sales guys in the past with real knowledge, I go for Techs for questions. Sales guys now many with nice hair and shirt but not the same back ground.

[Malcolm McLeod]

... Properly bonded surfaces can only be released by spraying acetone in a toe hold and working it apart. ...

I have taken laminate off of counter-tops in 2 or 3 houses using a heat gun. Probably not any faster than acetone, but it smells better.

[Mel Fulks]

Warren, thanks. Yes ,some of the stuff will last a long time. And I’ve seen good laminate guys find non sticking places in their own work
before It left the shop. And when sales guys are pushing the THICK plastic tops, “solid surface” stuff, THEY will say the contact stuff is
inferior and falls apart! Even though ,back at the shop , guys are filling laminate orders they sold ! There are customers who prefer
laminate but won’t buy it because “it falls apart”. Years ago shops were selling inlaid laminate and it was tedious work. CNC could bring
that back, and plastic resin glue would make it permanent. “Permanent? We can’t make no money like that!!”

[Richard Coers]

That stuff is a permanent bond. Properly bonded surfaces can only be released by spraying acetone in a toe hold and working it apart. Swearing, screaming and whining is warranted. I have worked with way too much laminate. :rolleyes: So the cooler the surfaces the longer to open time. No glue should release when pressing firmly with your finger. Not tacky. Some laminates also soak the glue so I would often apply a second coat to that a well as the sub-strait.

Best of luck.
Try putting a black laminate table under a big south facing window in the summer time. Then test it for bond. Contact cement can also be removed with a heat gun, or that window situation.

[Warren Lake]

if you want to read the pros, not sure this will open.



file:///C:/Users/Warren/AppData/Local/Microsoft/Windows/Temporary%20Internet%20Files/Content.Outlook/JA6CSQI9/Contact%20Adhesives.pdf

[Carroll Courtney]

There is always change that can you have is old, I always try to buy from place that sells lot of it. You know like HD or Lowes, I purchase from Ace before but it was old would not stick

[Warren Lake]

done commercial stuff past where i know an edge would get heavy wear daily so used contact up to close and last few inches or so white glue and clamped.

[Mel Fulks]

done commercial stuff past where i know an edge would get heavy wear daily so used contact up to close and last few inches or so white glue and clamped.

Agree! If the edges are good ...the middle ain’t goin’ anywhere. It’s kinda’ like the way sheets are held on a bed ....except without the
contact cement !!

[Richard Coers]

done commercial stuff past where i know an edge would get heavy wear daily so used contact up to close and last few inches or so white glue and clamped.
I did a few guard stations for a Federal Prison back in the day. First 2" had to be glued with PVA glue, the rest was okay with contact cement. I've been cut breaking up some scrap laminate, no need to explain that requirement to me!

[Warren Lake]

I wasnt I figured there are a few other people here

[Warren Lake]

Mel rings a bell on bed sheets. I have five layers and almost want to sow them or button them in place. Once told im a travelling Willbury. Seinfeld had a line on one you tube about "ever look at your bed sheets in the morning, nothing restful about that" whatever words he used.

[Larry Edgerton]

Done a few thousand feet myself, and my thoughts are that you put it on before the solvents were evaporated. Like Warren, I made some mistakes along the way and that was one. I now use a spray setup and will never roll again!

[Warren Lake]

no I didnt make mistakes I learned from old guys who learned from old guys they already knew it before they taught me.

[Warren Lake]

Ive never rolled it sprayed from day one and the brand I posted. Modified primer gun to pressure.

[Gordon Stump]

Try putting a black laminate table under a big south facing window in the summer time. Then test it for bond. Contact cement can also be removed with a heat gun, or that window situation.

I should have said...."can be released with acetone". There are always different ways to do things and I am certainly no laminate expert. I actually hated having to work with laminates. Many years ago I bought a new contact cement product. It was pink. A very sweet 85 year old commissioned me for a small kitchen job and picked a really expensive white slate Formica. After a few days the curved edging came off. Repaired on site. Then the horizontal parts started popping off. Repaired on site. This continued for awhile. It was very bad. I still have nightmares of her calling on the phone.

[Warren Lake]

never had it fail ever and I did lots. Helmitin brand, pink or natural always sprayed. The worst is over spray still on some machines that were within my firing range. I make a mess at times when I work but the work comes first.

Gordon I get what you are saying often I breeze in type fast then there is a wrong word. I said the pro stuff up above and meant some pro stuff. I go back to edit after and half the time this site wil not let me edit and cant even see my post, now i went back in to respond to what you said here and its works as it should. ??

The old guy I knew best had a grade three education and taught himself to read with newspapers on store windows. All was bombed and the war ended school for him. He could not even speak english when he worked for one of the largest companies in toronto but learned fast. The lawyers, brought him all the contracts to review and he said he changed words and made it so it was best for the company so they would not get stuck. That made me realize just how the wrong word changes the whole thing. He had no education but he understood. His answers at items were different but he saw the bottom line.