Again I come to you guys for help.
We’ve made some hollow core doors using 1/4″ birch ply for skins. We needed hollow doors for the weight issue. 8′ x 34″ x 1 3/8″ – held to free standing cabinets with piano hinges. I had to veneer the doors with paper backed rotary cut birch veneer to solve a color match issue. Here’s the problem:
These are hollow core doors, so I couldn’t put them in a press to veneer them. We used WillsonArt contact cement, but the veneer is blistering. I can strip off the veneer and get new sheets, but what kind of glue do I use? I’ll need a press for plastic resin, and the hollow core and square footage of surface area makes hide glue difficult at best. I suppose with the hide glue I could keep it activated with an iron as I screed it down, but I’m taking a chance scorching the veneer.
Is there a product that applies like contact but has a more rigid bond? Something that is not heat activated and/or doesn’t require a press? If I were to fill the hollow portions of the door with expandable foam do you think that will create a solid enough surface to press to?
I’ve read through most of the archives here, but figured I should ask on the forum. Would anyone recommend the spray can stuff like 3M or StaPut?
Any advice is appreciated.
Ed. Williams
Replies
Ed,
Not sure on what glue type - I'd think the contact cement would have done the job. Tried the spray stuff once and it didn't provide sufficient adhesion to hold the edges of the veneer down.
I'm wondering, however, about using expandable foam to create a more rigid surface. Don't think it would help unless it completely filled the void and can't imagine how you'd do that without seriously damaging the door. Hmmmm....
Jeff
Ed, try this for an experiment. Buy white PVA at Home Despot or wherever, about $8-- $10 a gallon-- Elmers Glue-All is one brand. While you are there get some of those small toss away foam rollers at about $2 a pop, and a few wee plastic pails.
Pour some PVA in a pail, add about 10% to maybe 20%'ish of clean water, stir it up until you get a thin unbroken stream running off your stick. Slop some of this muck on the ground and spread it out evenly with the roller-- avoid lumps and dirt. Do the same on the veneer. Toss the roller in a pail of water and clean it.
Wait until the glue is dry. Lay and centre the veneer over your ground. Warm up an iron-- not too hot-- the bottom end of the cotton setting should be about right, and starting in the middle iron the veneer down--radiate out from a central point. The iron will reactivate the glue, and it should bond well.
You might find it helpful to slip some plastic laminate or something similar under either end away from the centre, and keep slipping it out as you work the veneer down. If you've got a veneer hammer, that should help a bit too.
If you find the experiment doesn't work for you on a small piece, get back and no doubt I or someone else will think of another method that doesn't involve a veneer press, ha, ha.
It sounds like your contact cement failure might have been due to the finish that went over the top, e.g, pre-cat lacquer has solvents in it that can dissolve contact cement. I've also heard of contact cement failure in high heat and humidity locations. Just a couple of thoughts. Slainte.
Website The poster formerly known as Sgian Dubh.
Ed, I've used hide glue for various veneer jobs, and you can use a damp rag to keep the veneer from scorching. But I read something in here last week about using yellow glue the same way as hide glue. So I tried it. I put glue on both pieces, let it dry, and then placed them together. Then I used an iron to reactivate the glue, and presto. It worked great. I just tried today to rip off an edge banding applied this way, and the wood just didn't budge. It would only come off by splintering. I'm not sure if this would be feasible for such a large door, but it's just a thought.
Thanks so far - good advice from all.
We were surprised too that the contact seems to be failing. This is the second attempt. The first veneer we bought blistered also and we got the supplier out to the shop and he was surprised too. He said it may have been the fact that we were using laminate rollers to put it down. He said we should use a board on edge to press it on. He said it gives much more pressure per square inch than a roller can. So we did that on the second try and we still have blistering. The first one blistered overnight in our shop. The humidity hasn't been a factor until this week. It's been a beautiful Spring in Texas this year.
I was informed of the new blistering today by the painter. He called from his shop to say it was happening. I haven't seen it yet, but will go by tomorrow as see for myself. The product he is using is not alcohol based, but if I hadn't seen the first effort blister before stain, I would be inclined to believe it was the culprit.
None of the edge tape we put on came off, but then it is heat activated.
I'll try a test of the PVA glue tomorrow. Is that just Elmer's regular white glue?
Ed.
Ed, it was Titebond regular. I never would have tried it on my own, but I'm glad I did. As strong as the bond was, I'll be suprised if something goes wrong. But I'm a believer in Murphy's Law.
"Is that just Elmer's regular white glue?"
Ed, that's what I said. Elmer's Glue-All. Outwith veneering, I don't find much use for PVA type glues down here in Houston-- I can't imagine Dallas is that much different, but maybe it is? For me, there's too much creep induced after the transfer of the finished piece of furniture from a hot and humid workshop to air conditioned house or office, and the yellow stuff in particular goes off far too quickly, especially in those well known misery months to be of much use unless it's a quick glue and screw job.
The cheap old white Elmer's seems to work better for me than the yellow versions for general joinery-- it has a slightly longer open time, which can be extended by adding a bit of water-- helpful in a complicated assembly and glue up, and for veneering it's very useful. Just got to watch out for bleed through, but as you're working with paper backed veneer, that shouldn't be a problem. Slainte.Website The poster formerly known as Sgian Dubh.
Richard, Elmers, huh. I'll try it. Tell me, could I have much problem on creep, using the yellow on an edge banding, with the grain running across the edge and not around it? I'm using it to wrap quarter-sawn white oak on the edges, to show the flake on all sides. Any help would be greatly appreciated.
I saw the damage today. All the blisters laid back down with a little thumb pressure. I told the painter to finish and I would pick them up on Monday. I'm hoping that the blisters I laid down today will stay down. That doesn't mean there won't be new ones on Monday.
However, the painter did say some words of encouragement, I guess. At least the doors have had one coat of thin whitewash stain (water based) and one light coat of sealer (not water based). He's thinking that maybe now that it is sealed, we shouldn't have any more problems. I hope he's right.
Ed.
Your painter, Ed, is hoping you'll just say okay, and you'll let him off and pay him in full, and he'll be gone with that old tail-light warrantee-- as long as you can see my tail lights, it's warantee'd-- did i spell that right? Assuming that he didn't lay the veneer in the first place, and he just slapped some finish over the top, I wouldn't blame him myself.
If you avoid dealing with bubbling veneer now, it'll come back to haunt you, and kick your #### in a big way. It's quite common for a coat of finish to make the 'problem' disappear-- for about a fortnight or a month.
Then you're in serious trouble. You need to sort out the problem, now. Sorry feller, but I mean it. No joking. Slainte. Website The poster formerly known as Sgian Dubh.
Richard,
I know I'm screwed. The painter is doing this gratis. He's a good man.
I'll hang the doors to get the customer back to normal for a while and make some new doors.
The customer has been more than understanding. They still owe me $2500 but I don't think I'll try to collect. It's been too long and too much trouble for them.
What am I saying! How about a 25% discount? That's fair don't you think?
Ed.
Those mess ups hurt, Ed, and the 25% discount sounds pretty fair. If you plan to replace all the doors anyway, you might experiment with at least one of the existing doors by stripping off the current paper backed veneer using lacquer thinner, clean off the contact cement from underlying ply or skin, and re-veneering. This might be more effort than it's worth, but it seems worth trying on one. Slainte.Website The poster formerly known as Sgian Dubh.
creekwood, all PVa's have a tendency to exhibit their unfortunate creeping nature, via either moving out of place during changes in humidity, or showing a row of pimples at the glue line, and worse in laminated glue ups.
From what you describe, you might experience creep, and it's something to watch for in this piece that you've made. If your experience is that creep is not a problem, then continue using PVA type glues.
If you want to be assured of avoiding creep as a potential source of trouble in the future, use a non-creeper, such as liquid hide glue, urea formaldehyde, polyurethane, etc.. Each glue has its shortcomings though, e.g., polyurethane needs firm cramping pressure, and apart from hide glue, and PVA, all these glues are not too easy to fix 10 or 50 years down the road. It's the usual case of selecting the best for the job in hand from a series of viable options. Slainte.Website The poster formerly known as Sgian Dubh.
Thank you, Richard. I'll keep an eye on it and see if there's any problem. I used hide glue for hammer veneering on most of the piece, but thought I'd try PVA on this one aspect. Seemed like the thing to do at the time.
Again, thanks for your input.
Why don't you use liquid hide glue, either Titebond/Franklin or Patrick Edwards Old Brown Glue. You have plenty of open time and any blisters can be dropped the next day with a household cloths iron and a j-roller.
Stephen Shepherd
http://www.ilovewood.com
Depending on the type of hollow core door they are, you can (or might) be able to use a vacuum press. The thickness of the caul along with the amount of vacuum press you use should be able to do the trick. just don't practice on the final part. I have done it before , but it has been about 4 years ago and I don't remember how much vacuum I used. I haven't heard back from the client, so I assume there has been no delaminating. Also drilling small holes in the face will help ease some of the internal stress from having an unbalanced vacuum
Hey migraine,
I considered vacuum pressing, but it will just collapse the door to pieces.
Ed. Williams
If the core of the door is honey comb, there is a possibility that it will not. Part of vacuum forming is the cauls that actually press the veneer to he door and the honey comb as a stiffener. If the thickness of the caul is insufficient, it may cause indentations between the center of the honeycomb. If the thickness of the caul is too thick, the veneer may not get enough pressure on the door to adhere. The amount of vacuum pressure is important also. As I stated earlier, it is trial and error. I am not pulling your leg. I have done this before and it works. Take your time. Part of learning to use a vacuum press is getting used to what does and doesn't work. I have imploded my share of molds in the past. the last one being 4" wide X 8'long X 21" high
migraine,
Thanks for the advice. We made these doors ourselves so there is no filler. Just a ladder stile and rail frame skinned with 1/4" plywood instead of the usual 1/8" door skins. We felt that using the 1/4" plywood instead of skins would eliminate the need for a core filler and it did. The doors were fine. Nice and flat. The original problem was the color of the birch plywood from one door to the next. That's why we thought a matched pair of veneers on top would solve the problem. Little did I know that the glue we used would be such a bad choice. The veneer manufacturer said it should have worked and so did the glue company.
I don't own a vacuum press although I have access to one. We don't really do enough of this kind of work to justify the expense. I usually just make positive and negative moulds and clamp them together using plastic resin glue as the adhesive.
I'm starting to worry about a radius reception desk we just finished. We used contact cement on those too. They haven't been stained yet, but I'm anticipating the same problem.
Ed.
If the doors are still an issue, can you veneer the 1/4" plywood and the veneer the doors. If you have a problem with the reception counter, press the veneer on to a bendable/kerfed substraight and contact cement/ panel adhesive that to the reception counter. Anderson International Trading (Anaheim, Ca.) sells a new product for that application. I believe the product is made in England, but I'm not that sure.
You can but a small vacuum pump, a controller, a check valve, find an old tank for a surge tank(like a compressor tank, booster tank, etc). a piece of 1/2 braided hose, a ball valve. and a piece of patio vinyl glue with vinyl glue and the ends left open. All of this for under $500. I believe that one of the vacuum pressing companines in Mass. sells a controller for about $275. The pump for about $100 at graingers. Once you have a press, it is amazing how many things can be done on a press.
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