Bubbles in Laminate on Steel Doors

Troubleshooting a bubble issue with laminate applied to steel doors. January 24, 2010

First of all, I am very new to laminating in any form, so please pardon my ignorance, I have found that it's a very steep learning curve. I work for a company that refinishes furniture for hotels, govt, universities, etc. and from time to time, we get a job that is out of our normal realm work. Right now I am working on a contract to re laminate 102 doors for a military hospital. Basically I was introduced to the project manager, my boss gave me some basic instruction as far as how the process should work, and was told "you're a sharp guy you'll figure it out." For the most part, everything has gone well. The customer has been happy with the quality of my work, I am constantly refining my process to improve the quality, and speed of production and have it down reasonably well.

The problem I am running into is one of the first nights we were here we overestimated how many doors we could do in a day and ended up gluing the back side of six doors down about 11pm (we're working outside by the loading docks) from what I can gather, I think the effect of the acetone evaporating out of the glue cooled the doors down to the point that condensation formed on the door. Now, as I'm sure you have guessed I have some bubble issues to deal with. I have to be out of here four days from now and still have 22 more doors to do in addition to fixing the bubbles. My partner and I have been able to average about 5-6 doors per day which doesn't leave me much time to deal with the bubbles. Also, because this is a pretty busy hospital, I will have to make the repair while the door is still hung in the room, and there will more than likely be a patient in the room as well.

The obvious answer is to peel the laminate off and re-do it, but time constraints, and the hospitals patient load don't allow for that. I have been researching this for a couple of hours now, and have seen some people mention heating it with an iron, drill a hole and inject some adhesive, cut a slit in it and re-glue it, etc, but most of this was related to fixing bubbles in laminate flooring. Thus far I have tried punching a small hole in the laminate to allow the air to escape and rolling it back out. That worked on one door (at least so far), but not on another I tried it on.

Now, if my ignorance to the art of lamination hasn't already made itself apparent, it will be readily apparent now. From what I understand, the laminate we're using is Formica brand I think. I have been told that it is vertical grade (maybe 1/16 of an inch thick). The brand of adhesive we were using at that point was Formica brushable contact cement. We have since switched to some Wilsonart adhesive which seems to be working better. It is being applied over the old laminate finish on the doors (there is a perma clad metal sticker on the doors if that helps) We are preparing the doors by first filling in any gouges, chunks, etc. with bondo and then sanding the entire door with 60 grit paper on a d/a sander. Then we brush off the dust, and wipe it down with denatured alcohol. Then the adhesive is applied with a roller to the door and sheet of laminate. It is rolled out with 3 wheel hand roller. Any advice, help, pointers, lectures that anyone could provide will be greatly appreciated. I have learned a lot on this project, but still have a very, very long way to go. Is there something I can inject into a small hole through a syringe to re-activate the existing adhesive? Will ironing it out work? Am I completely screwed?

Forum Responses
(Laminate and Solid Surfacing Forum)
From contributor A:
Yes, so far as I can tell from your post you are doing everything correct. Heat from an iron should work. I had a similar problem long time ago. Obviously put something between the iron and the surface! Depending on the size of bubble, you may also have to put a small hole and then iron out towards the hole. "Seamfill" should hide your hole and is available from your lam.

From contributor S:
First, it usually doesn't pay to re-laminate doors. It would probably take less time to make them from scratch. Now for your problem, how much time are you allowing for drying? You should be able to place a piece of paper against the glue and pull it off without sticking to know when it is ready. If you apply the glue too thick then you might have problems where it dries on the surface but it is still wet under. Once you apply the laminate the glue won't dry without air getting to it, therefore you get bubbles. If this is the case then the iron idea won't work, because it was never dry in the first place. The iron idea is meant to reactivate the glue so it will stick. You would have to remove the laminate on the one that won't work with the iron. It still pays to try the iron first and then if that doesn't work then take it off and start again.

From the original questioner:
Thank you for your responses. I tried the iron trick along with several other methods. None of them worked. I've got some more laminate ordered, so I'm just going to have to re-laminate the affected doors. I am curious as to what caused the bubbles though. Please let me know if this makes sense. The area they gave us to work in is in direct sunlight the majority of the time we are working on the doors. Although the ambient temperature is only between 75 and 85, the doors are getting very hot due to the radiant heat energy from baking in the sun. I think what is happening is the doors are expanding in the heat. Then we are applying the laminate to an expanded door. Once we bring them back inside and the doors cool off they shrink back to their original size causing the laminate to pull away from the door in a long bubble down the center of the door. This is the only logical reason I can come up with. I think I am doing everything else right. We are thoroughly prepping the doors. The adhesive is applied in as thin and even of a coat as we can, using rollers. We are letting it dry to the point it won't stick to your fingers if you tap on it. I am applying as much pressure as I can when rolling them out. I just can't think of any other reason they would bubble in the fashion they are. Thanks again for your help.

From contributor S:
It is possible that drying it in the sun is drying the surface quicker and not the glue underneath. It appears dry to the touch but it is not fully dry. If you want to find out what caused it, I think you should use a knife to remove the laminate from at least one door so you can see if it was a drying problem. If you use thinners then you will not be able to see what was the problem was.

From contributor U:
Some contact cements don't adhere well if they are allowed to dry too long before layup. I've had problems with this, particularly with water based cement. I would guess that your layup window is fairly short in that environment.

From contributor R:
Another problem could be the three wheel roller. It does not allow enough pressure to be placed on the surface. You should use a single wheel roller. I know it takes more time to roll out the laminate, but a three wheel roller gives you less lbs. per square foot pressure on the surface. When you put pressure down on a three wheel roller it puts your spreads your weight over a greater area thus less lbs/sq.ft.

From contributor R:
In your post you talk about bubbles under the laminate but do not describe their size or location. Then you mention a long bubble down the center of the door. The doors gather heat during the time they are in the sun and expand slightly. Then you put the laminate on and it is probably also hot. Then the door goes inside where it is cool and both the laminate and the steel door contract, but not at the same rate. The steel door will contract more than the laminate and something has to give so the laminate pops loose and buckles, generally in the middle of the panel. If this is your problem then you will probably have to peel one side of the door in towards the bubble , re glue and roll the laminate out again. Both the steel and the laminate will have stabilized by now and the problem should not reoccur.

Try sharpening a small putty knife and use it to peel the laminate, it works better than a thick blade knife. Also squirt Lac-tall into the joint and it will loosen the contact quickly. After you get the panel loose, use a hair dryer to dry the glue and reactivate it, roll the laminated back down and go home.