I recently started to use a water base and I tried 3m fastbond. I used a roller for one coat and let it dry for 30 minutes. It didn’t seem to stick as well as solvent. I took a sink cut out one week later and was able to peel the laminate off. Is this normal, or should the bond get better in time? I am wondering if I should I do two coats, and also, how do you know when it’s dry and ready to recoat or apply laminate?
From Jeff Pitcher, forum technical advisor:
Quite often I find that when a customer switches adhesive, they begin to look more closely at their glue-ups. This often leads to the realization that they have been getting sub-standard bonds for some time. The up-side of this is that it often can lead to better gluing practices.
Unfortunately, many customers simply dismiss the new adhesive as being somehow inferior and neglect to look at their process. In the case of fastbond 30, there are thousands of shops around the country who use this product quite successfully. WB contacts operate differently than other contacts, and there is definitely a learning curve. I would suggest working closely with 3M to perfect this product's use.
I used FB30 for a long time. It will change color when dry, and shouldn't be even a little bit sticky or tacky when you put your hand flat down on it. If you do very much laminating, or do a moderate amount at one time, consider switching to a pressurized canister spray. It dries almost on contact, and gives a very good bond.
Also, regarding your specific problem, some things come to mind. Laminates, when hand rolled, should be done from the center outward to allow trapped air to be expelled. This is more important than it might seem. Second, when doing a cutout, you can tear loose the bond with an upstroke blade. Use a jigsaw with a downstroke blade to ensure this doesn't happen. Lastly, you can sometimes reactivate contact cement by heating it and then applying pressure as it cools. I've found that localized pressure, such as working around the area with a vice clamp, works much better than does a roller.
Comment from contributor B:
I used water-based Fastbond 3m for some years. What worked best for the crew was to get fans available at home improvement stores that really move the air. Each bench had one for each worker. One important thing is to get the Fastbond dry before the dust settles on it. That was our number one problem.
There were other issues as well. When doing stacked edges it was easy for the material to seep in. If you seal it first with a light coat and leave it a few minutes, then add another light coat and leave it for a few minutes, then a final coat and use a foam brush to spread it, you get a nice solid grip.
Make sure to separate the pieces as fast as you can so that they dry without sticking together. If only doing one edge, you don't have to do this, but I recommend it. Always give edges this one, two, three treatment and you'll be great. Some guys used old coffee cans (medium ones) and cut a hole in the lid for the wooden dowel of the 4" foam brush to stick out. These would last for weeks, and actually get better with age until they finally failed. They seemed to start to hold more after a few days.
Something I found that an advantage of this was to build a cabinet and laminate the interior afterwards. We did some all plywood interiors for restaurant conditions and I was able to cut out, joint, and pre-fit all the inside pieces within reasonable tolerances fairly quickly. Then I would spray the contact on super wet and then take the piece and slap the wet thing into the cabinet and hand press it everywhere and then peel it out immediately. Next was to brush out the laminate and leave the plywood as is. If you leave it for more than a minute while pressing it, you almost can't get it out.
The number one thing is to make sure you don't get big thick puddles or rivers of the stuff (using the spray can help, and a 4" foam brush can help make up for errors). Sometimes we would spray it on and use a foam brush to smooth it out just to make it the best as possible. When these things did stick, they were not coming off.
There are lots of other things I can't remember now, because it has been some years, but I used it for seven years and found that, like with all things, what it lacks in one area can be offset by strengths in another.
It was sometimes a pain to have to wait the five to 10 minutes for the fan to do its thing, but all of us got used to planning our work so that while one thing was drying up, we were either routering on some other product somewhere away from our work, or else preparing something else.
Dust is the biggest problem. Make sure to get fans on it, and get it dry as soon as you can. It works great and you'll love it. We used the metal caged high volume fans, not the plastic casing ones for home.
They say you can let it sit longer than the prescribed time, but then you have to really apply a super amount of pressure to get the stick you want. I think you are intuitively right that you want to stick it at just the right tackiness time. Even so, all of our workers, when doing tight curves, preferred the gnarly solvent base because of its initial tack. One person finally decided to just clamp the edges (on curves) and let them curve overnight before unclamping them and that helped, if that is possible.
Another woodworker who had trouble with laminate shrinking on counters, left 2" around the edges of the counters dry and applied wood glue, and he said you could never get that laminate up. I found the low initial tack to be a liability but clamping overnight did help a lot. Make sure to put it on at just the right time of tack. If it’s too wet it seems it has a hard time curing. It’s not hard to get it right, it just takes practice before doing curves. Once you have the feel for it, it is not that big of a deal. I would definitely recommend getting used to it on flats.