I applied a beautiful maple veneer on the Concert Grand cabs, however the face on one cabinet and a side on the other have developed severe wrinkles!
I believe that I can pull the veneer off of the MDF without too much damage... does anyone have any advice for prepping the MDF for a second round of contact cement and veneer? Pulling back about 5 inches of the veneer, there's enough residual contact adhesive on the MDF that I don't know how to remove.
The good news is that I have enough un-used veneer left over to complete the project - if I can get rid of the glue (or smoothly even it out) from the cabinet!
I believe that I can pull the veneer off of the MDF without too much damage... does anyone have any advice for prepping the MDF for a second round of contact cement and veneer? Pulling back about 5 inches of the veneer, there's enough residual contact adhesive on the MDF that I don't know how to remove.
The good news is that I have enough un-used veneer left over to complete the project - if I can get rid of the glue (or smoothly even it out) from the cabinet!
Yup, not enough pressure. You might well still be able to fix this if you can get enough pressure on the bulges. Do you have a J roller?
You can dissolve contact cement with contact cement solvent, usually available where you got the glue.
However you can also use yellow glue with ease if you use weights and a J-roller.
However you can also use yellow glue with ease if you use weights and a J-roller.
Frankross, There are a variety of approaches you can take to deal with this. Solvent was recommended in an earlier post, however it sounds as if you are working with a very thin, pure wood veneer and I would be dubious about using a solvent, as it may soak through the veneer and possibly stain it. In addition, solvent will invariably soak into your MDF, and no matter how dry it gets, may cause adhesion problems with new contact cement. It also may create an undesirable swelling or weaken your MDF, especially if you use too much......If you want to remove the dried contact cement from your MDF, I believe meticulous sanding of it with a high grit sandpaper is your answer, being careful not to create a concavity in your material, which would translate into a concave finished surface..... One approach may be to slice the wrinkles with a razor blade or X-acto knife lengthwise and then inject a fluid glue in, then use a roller to press the wrinkle down, then weight it down on a flat surface until it dries, then sand with a 400 or greater grit sandpaper to feather the seam. The way I would attempt to remove contact cement would be to tediously and meticulously sand it off with a high grit sand paper............but, if I was looking for a flawless surface, I would bite the bullet,..........rip off the bad veneer, sand the MDF clean of the contact cement and apply a new sheet using the dowel rod method, and not rush it. I work with contact cement and I screwed up an application of laminate on one of my boxes and fortunately it was repairable.......Once the surfaces touch, thats it man. You started another thread about wax paper and mentioned you had about a half inch extra on the edges.........Is there any way you can use a bit larger piece of veneer? Also you may want to consider the dowel rod method to apply your new veneer because it allows you to work in a more controlled manner, slowly, and not rushed, which will assure you of good contact, with the ability to give you good pressure on your cabinet and provide you the accuracy of placement........Nothing worse than misplacing veneer on your boxes when you use contact cement..............Respectfully......Omni ..........P.S. I would recommend a solvent based contact cement. There are waterbased contact cements out there, however, humidity creates a variety of adhesion problems. You live in Pennsylvania, and I am in Ohio, and the last few days here in Ohio were at 85% humidity, must have been similar in PA?
Can I guess??? You put oil stain over contact goop... and then finished with polyurethane?
Listen to very little spoken here...
Been there... send a PM if you like.
🙁
Listen to very little spoken here...
Been there... send a PM if you like.
🙁
Thanks everyone, I do appreciate the feedback!
I keep a dehumidifier running all of the time so the enclosed room (with ventilation ducts and outward blowing fan) is really not that humid. After applying the adhesive to both surfaces with a 1/4" nap roller, let sit for 20 minutes, I used a straight 2X4 with a lot of force to "scrape" across the surface, working from the center out to the edges, to get a good bond. Everything went fine until I sprayed the MinWax polyeurothane and the wrinkles started to appear. No stain was used for this project (I wanted the natural look of Maple with a satin clear coat finish). I was shocked to say the least, that's the first time this has ever happened to me.
Btw, I used the traditional method of laying strips of 1 X 2 wood under the 10 mil paper-backed veneer (didn't use wax paper) to get it into position. The 1/4" extra was more than enough to work with (no problems with alignment).
I'm curious though, if I pull the veneer off, will the contact adhesive dry out over the course of a few days or a week, to make sanding easier? Or will it remain "rubbery"? Also, will it hurt to apply contact adhesive over the old contact adhesive if it's relatively flat, or is this asking for more problems?
I keep a dehumidifier running all of the time so the enclosed room (with ventilation ducts and outward blowing fan) is really not that humid. After applying the adhesive to both surfaces with a 1/4" nap roller, let sit for 20 minutes, I used a straight 2X4 with a lot of force to "scrape" across the surface, working from the center out to the edges, to get a good bond. Everything went fine until I sprayed the MinWax polyeurothane and the wrinkles started to appear. No stain was used for this project (I wanted the natural look of Maple with a satin clear coat finish). I was shocked to say the least, that's the first time this has ever happened to me.
Btw, I used the traditional method of laying strips of 1 X 2 wood under the 10 mil paper-backed veneer (didn't use wax paper) to get it into position. The 1/4" extra was more than enough to work with (no problems with alignment).
I'm curious though, if I pull the veneer off, will the contact adhesive dry out over the course of a few days or a week, to make sanding easier? Or will it remain "rubbery"? Also, will it hurt to apply contact adhesive over the old contact adhesive if it's relatively flat, or is this asking for more problems?
J-roller ? They never produce enough pressure for an excellent bond, his use of a 2x4 edge was a better choice because more pressure was applied from that small edge than you would ever get from a j-roller. One question, was this raw veneer or did it have a backing? I don't recall seeing this info. Raw would be more likely to let the Poly spray get thru and react with the contact cement. Paper back or some other type of backing that keeps the finish away from the cement is better. Did you use water based contact cement? Water based is less reliable. Spare the cement ,spoil the job. ALot of good articles on the net on veneering. Good Luck
Frankross, It was cool to see you clarified your techniques, and it appears you have employed some good methods. How long did you wait to apply your poly finish after you applied the veneer? The scenario you describe in your last post is indicative, perhaps, of the solvents from the polyurethane seeping through your veneer to the contact adhesive, and loosening the bond.... My experience with adhesives has shown me to allow them to cure for a day or more, rendering them impervious to further treatment. In a case of spilled contact cement, I have observed that it does harden further over time. This should make sanding it off more predictable. I would not apply new contact adhesive over the old stuff until I removed as much as possible, and I would still stay away from a waterbased product, wait a few days after applying the new veneer to allow the adhesive to cure, then proceed with the poly spray with multiple light coats, instead of heavy coats. Light coats of the poly finish will provide less chance of its' solvents seeping through your veneer to the contact cement. The instructions on the can of contact cement may say that one can rejuvenate the adhesion of dried cement with the application of more cement, but I think there is only a short window of time for this to work. Even then, I believe this is a stretch. I hope you get through this hassle............Respectfully........Omni
Budwiser - the veneer is 10 mil paper-back. I used DEP contact cement - I was told to use the "original" formula. I don't recall if it's water based or not, but they do offer another newer type of contact adhesive that I was told (recommended) not to use.
Omni - I waited about a day and a half before spray-bombing the poly. Good pointers, so tonight I'll pull the veneer off and let the glue dry out as much as possible before sanding. Never having sanded adhesive before, I'm thinking 80 grit on an orbital sander should do the trick? The board sander is out of commision and it's going to be some time before I get another.
If in fact the Original formula DEP is water based, should I consider using the new formula DEP Contact Adhesive?
Thanks again for the help.
Omni - I waited about a day and a half before spray-bombing the poly. Good pointers, so tonight I'll pull the veneer off and let the glue dry out as much as possible before sanding. Never having sanded adhesive before, I'm thinking 80 grit on an orbital sander should do the trick? The board sander is out of commision and it's going to be some time before I get another.
If in fact the Original formula DEP is water based, should I consider using the new formula DEP Contact Adhesive?
Thanks again for the help.
Among such products, the 'smelly toxic' stuff has a solid reputation for giving the best results... but now that ive been successful using wood glue, Im never using CC again.
The original DEP is in fact not water based, so you used the right one. You said you bombarded with poly spray? Multiple lite coats would be better with day drying time and light sanding between coats to keep bleed thru from getting to the glue. As the other post said wait some days for contact cement to dry before applying finish. Hope thing work out for you.
80 grit is a fairly coarse sandpaper, so be careful not to concentrate that orbital sander in one place for too long. It does not take too much pressure either, or you will find yourself creating concave spots in the MDF, which will translate to your finish. I just got my baffle boards primed for my topcoats.......what a hassle, and I am still not finished yet.......so I can certainly relate to your frustration........I am battling the urge to hurry it up, so I can get the drivers mounted to make my final impedance measurements for my crossover design..........but I've got to be willing to take the time to do it right, amidst all the setbacks.............I sincerely hope you get the fine results you have envisioned.........Respectfully..............Omni
Omni - good luck on your project. When you're finished Id like to see pics.
As I was afraid would happen, pulling the veneer also took some of the MDF along with it. Nothing too deep, but it's still noticable and pretty much pocked the entire surface. Though I'm concerned about the over-all appearance after applying the veneer, I'm more concerned about pockets where the veneer will not grab hold. 80 grit might be the only way out of this one, along with several coats of cement on the MDF to even out the surface.
Because the cabinets are so enormous building new boxes would be very painstaking. Hopefully I can figure out a way to resurface the MDF to the point that it will hold the cement evenly and still look presentable. Btw, test sanding with 220 grit using an orbital DA sander yeilded no results whatsoever, other than heating the cement and making it even more tacky...
As I was afraid would happen, pulling the veneer also took some of the MDF along with it. Nothing too deep, but it's still noticable and pretty much pocked the entire surface. Though I'm concerned about the over-all appearance after applying the veneer, I'm more concerned about pockets where the veneer will not grab hold. 80 grit might be the only way out of this one, along with several coats of cement on the MDF to even out the surface.
Because the cabinets are so enormous building new boxes would be very painstaking. Hopefully I can figure out a way to resurface the MDF to the point that it will hold the cement evenly and still look presentable. Btw, test sanding with 220 grit using an orbital DA sander yeilded no results whatsoever, other than heating the cement and making it even more tacky...
Frankross, can you post pictures of the pocked surface, and does this surface still contain adhesive ? The first thing that came to my mind was Bondo to fill the pock marks. It adheres well and sands like a dream, very smooth, and is made to accept adhesive products. It hardens quickly, so you have to work fast, however, you can add less hardener to slow it down a bit. Man, I'm bummin' for you, it seems that when it rains, it pours.............At any rate, with Bondo, if you deem it useful, there are a few special techniques you can employ with sheet film plastic and another flat board. In a nutshell, you clean your surface as much as possible, then you spread Bondo on it, a little thicker, trying to get an even coat down, then you lay the plastic film, mylar or such on top of the Bondo, then sandwich the whole thing with another flat surfaced board, pressing down slightly. After the Bondo hardens, peel the film sheet off, as the Bondo will not stick to the plastic film. This renders an amazingly flat surface of Bondo. Its Just a thought, without seeing your cabinet. BTW, how large of a surface are you dealing with? .............Regards..........Omni
Frank,
If the pock marks are small, less than 1/16" they should make little difference. Don't make an effort to fill them glue as this will trap more solvent down the road.
Try using a scraper to remove glue. You need not remove all of it, as a subsequent layer of glue will "restore" it.
Once you get this fixed. I would recommend a few things:
0) Let your contact cement cure for a few days... high heat and low humidity to drive out the solvents.
1) Do your first coat with a brush using un-thinned material. Just one thin coat. This will reduce the amount of solvent available to attack the contact cement. You could still spray it on... one light coat.
2) Let that first coat dry for several days... again, hot and dry. This does three things, let's the solvent escape, encourages this first coat to act as a shield, and gives the first coat a greater ability to "sponge up" solvents from the next coat.
Next time... try the PVA and iron method... you'll be a happier camper.
🙂
If the pock marks are small, less than 1/16" they should make little difference. Don't make an effort to fill them glue as this will trap more solvent down the road.
Try using a scraper to remove glue. You need not remove all of it, as a subsequent layer of glue will "restore" it.
Once you get this fixed. I would recommend a few things:
0) Let your contact cement cure for a few days... high heat and low humidity to drive out the solvents.
1) Do your first coat with a brush using un-thinned material. Just one thin coat. This will reduce the amount of solvent available to attack the contact cement. You could still spray it on... one light coat.
2) Let that first coat dry for several days... again, hot and dry. This does three things, let's the solvent escape, encourages this first coat to act as a shield, and gives the first coat a greater ability to "sponge up" solvents from the next coat.
Next time... try the PVA and iron method... you'll be a happier camper.
🙂
I really appreciate the support that I'm getting here.
Poobah - In some areas the pock marks are a little deeper than a 1/16th, but spread over areas of quite a few inches. After pulling the veneer and letting the cabs "air out" the glue seemed to be very thin and flat. I guess that's in my favor as I don't have globs of glue sticking up everywhere on the surface.
Scraping didn't work because the film of glue on the surface is too thin - actually much thinner than a piece of paper. But to the touch it is still noticable due to the tackiness.
Some time ago I tried using the PVA/iron method and wasn't happy with the results. Maybe I'll take some scrap pieces and try it out a few times, perfect that process and use it down the road. I can clearly see the advantages to using PVA, so it could be worthwhile.
Omni - I considered using bondo also! After sanding with some rough grit I'll see where I'm at - bondo just might work in some of the areas. I'm reluctant to use it, but if all else fails...
The surface is 19" deep X 52" high. The other surface is 36" wide X 52" high. Told ya they were monsters! But yeah, when it rains it pours.
Poobah - In some areas the pock marks are a little deeper than a 1/16th, but spread over areas of quite a few inches. After pulling the veneer and letting the cabs "air out" the glue seemed to be very thin and flat. I guess that's in my favor as I don't have globs of glue sticking up everywhere on the surface.
Scraping didn't work because the film of glue on the surface is too thin - actually much thinner than a piece of paper. But to the touch it is still noticable due to the tackiness.
Some time ago I tried using the PVA/iron method and wasn't happy with the results. Maybe I'll take some scrap pieces and try it out a few times, perfect that process and use it down the road. I can clearly see the advantages to using PVA, so it could be worthwhile.
Omni - I considered using bondo also! After sanding with some rough grit I'll see where I'm at - bondo just might work in some of the areas. I'm reluctant to use it, but if all else fails...
The surface is 19" deep X 52" high. The other surface is 36" wide X 52" high. Told ya they were monsters! But yeah, when it rains it pours.
this is why i stoped using contact cement years ago.only wood glue for me.i own about 50 clamps so it's easy for me.i hope you can fix the wrinkles-i know how frustrating it can be when you put some much time into a box and it starts to peel or wrinkle.
FrankRoss said:
I obviously don't know what type of scraper you used but I would recommend a little tool called a 'cabinet scraper'. A paint scraper will have trouble with tacky glue (as you discovered). A cabinet scraper will remove almost any surface material and leave a finish smoother than you can get with sandpaper (yes, even 660 grit).
A cabinet scraper is essentially a thin piece of metal, usually about the size of a 3"x5" index card. The two long edges are sharpened and the burr from sharpening is not removed.
You hold in in both hands (or use a special holder but that isn't necessary) with your thumbs on the back and your forefinger and middle fingers on the front. Angle the top away from you and push it away from you to scrape your surface. Only a little practice is necessary to get great results.
You will have to remove the tacky glue that sticks to the scraper after a few passes. Since the burr is still in the edge it WILL cut your finger if you try to wipe it off bare handed. Use a cloth or paper towel. Moistening the cloth or paper towel with mineral spirits may help to remove stubborn goop and it will evaporate cleanly leaving no residue on your scraper or surface.
Probably more info than you needed (or wanted!) but as a woodworker I'm a big fan of cabinet scrapers and they may be the most valuable tool nobody has ever used!
Bondo is a great surface filler. It has a lot of qualities that you might want for a project like this; once cured it is waterproof and unaffected by humidity, it is extremely solvent resistant (again once cured), it dries very hard and is easily sanded, it is easy to apply using a plastic spatula and should almost be smooth enough to apply the veneer over without sanding (though I still recommend sanding!).
You will probably have to sand the bondo rather than just use the cabinet scraper. I've had good results with the scraper on certain types of bondo (I think it was a type called 'long fiber') and unsatisfactory results with other bondos. Now I just sand them all.
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