Well, if some of you have followed some of my earlier posts, you will remember that I had some difficulty with veneer.
I built a practice box to try some different techniques and a few questions have come up. I tried using wood glue and an iron.
Heres what I did:
First Try: paint veneer with wood glue and let dry, paint mdf with wood glue and let dry. Apply veneer to mdf with iron.
Results: Excellent adhesion, but the veneer curled severly as the glue was drying.
Second Try: paint veneer with wood glue and let dry, then iron onto raw mdf.
Results: adhesion was okay, but not great, but again the veneer curled severely
Third try: Paint mdf with wood glue and let dry, apply raw veneer with iron
Results: adhesion was the same as the 2nd try, only this cured the problem of the veneer curling
Current experiment: I am applying a coat of glue to the mdf and will let it dry. I will then put on a second coat of glue on the mdf and let it dry. Then I am going to iron on the raw veneer.
Expected results: Hoping to improve upon the adhesion of the 2nd and 3rd results.
The glue I have been using for all of the above is Lepage Suregrip Carpenters Glue. As far as I know, its just everyday yellow wood glue.
Onto my questions,
1. I read alot about PVA glue for this iron-on method. Is the glue I am using PVA? Should I buy something else?
2. Is there a way to prevent the veneer from curling to try option 1 and 2 again?
3. Any other ideas of what I should try?
Thanks for taking the time,
Jeff
I built a practice box to try some different techniques and a few questions have come up. I tried using wood glue and an iron.
Heres what I did:
First Try: paint veneer with wood glue and let dry, paint mdf with wood glue and let dry. Apply veneer to mdf with iron.
Results: Excellent adhesion, but the veneer curled severly as the glue was drying.
Second Try: paint veneer with wood glue and let dry, then iron onto raw mdf.
Results: adhesion was okay, but not great, but again the veneer curled severely
Third try: Paint mdf with wood glue and let dry, apply raw veneer with iron
Results: adhesion was the same as the 2nd try, only this cured the problem of the veneer curling
Current experiment: I am applying a coat of glue to the mdf and will let it dry. I will then put on a second coat of glue on the mdf and let it dry. Then I am going to iron on the raw veneer.
Expected results: Hoping to improve upon the adhesion of the 2nd and 3rd results.
The glue I have been using for all of the above is Lepage Suregrip Carpenters Glue. As far as I know, its just everyday yellow wood glue.
Onto my questions,
1. I read alot about PVA glue for this iron-on method. Is the glue I am using PVA? Should I buy something else?
2. Is there a way to prevent the veneer from curling to try option 1 and 2 again?
3. Any other ideas of what I should try?
Thanks for taking the time,
Jeff
Weight down the veneer with something while drying. Stack books or something on it. It will keep it flat while the glue cures.
So your saying I should not use the iron-on method? I should apply the glue and then apply immediatly????
Another way
I'm not really a veneer expert, but I've never had trouble when I've done it. Made a veneer covered rack cabinet some years ago, and it worked great; still looks wonderful. Same with the base for some speaker stands.
Not familiar with the Iron-on method with PVA glue. FWIW, I used DAP Weldwood contact cement. Paint both surfaces, let dry about 10 minutes, then stick them together, rolling with a small wooden veneer roller to get really tight adhesion. Sticks like no tomorrow. Probably less than $10 at Home Depot for a 16 oz. can.
The only drawback to my mind is that the stuff is very volatile and has some nasty chemicals in it. I found that I was allergic, and itched like crazy for two days after using it. The next time I used a respirator and made sure I didn't get any on my hands, worked with good ventilation, and had no problem.
I'm not really a veneer expert, but I've never had trouble when I've done it. Made a veneer covered rack cabinet some years ago, and it worked great; still looks wonderful. Same with the base for some speaker stands.
Not familiar with the Iron-on method with PVA glue. FWIW, I used DAP Weldwood contact cement. Paint both surfaces, let dry about 10 minutes, then stick them together, rolling with a small wooden veneer roller to get really tight adhesion. Sticks like no tomorrow. Probably less than $10 at Home Depot for a 16 oz. can.
The only drawback to my mind is that the stuff is very volatile and has some nasty chemicals in it. I found that I was allergic, and itched like crazy for two days after using it. The next time I used a respirator and made sure I didn't get any on my hands, worked with good ventilation, and had no problem.
for a large area like speakers
use 3M Contact cement.
You can also buy epoxy in the gallon size at automobile part supply stores. I guarantee this will work, but it's expensive and you will never, ever get the veneer off. When the original swan speakers were described in Speaker Builder (was it 1984) they used West Epoxy for the veneer.
You can fashion a veneer press to work with wood clamps. Take two sheet of 1/2" plywood a little longer than the surface you are working with. Lengthwise, attach 1 x 2 's to one side using #8 screws, with the narrow side perpendicular to the surface. Counterbore the holes so that the screw heads do not come into contact with the veneer. Slightly plane down the ends of the 1 X 2's so that they have a slightly bowed look. After the veneer is applied you clamp the two sheets of plywood to the sufarces, smooth side facing the veneer. You will find this "press" works quite well if you are using a slow-setting adhesive like epoxy. It was described in Fine Woodworking a long time ago.
use 3M Contact cement.
You can also buy epoxy in the gallon size at automobile part supply stores. I guarantee this will work, but it's expensive and you will never, ever get the veneer off. When the original swan speakers were described in Speaker Builder (was it 1984) they used West Epoxy for the veneer.
You can fashion a veneer press to work with wood clamps. Take two sheet of 1/2" plywood a little longer than the surface you are working with. Lengthwise, attach 1 x 2 's to one side using #8 screws, with the narrow side perpendicular to the surface. Counterbore the holes so that the screw heads do not come into contact with the veneer. Slightly plane down the ends of the 1 X 2's so that they have a slightly bowed look. After the veneer is applied you clamp the two sheets of plywood to the sufarces, smooth side facing the veneer. You will find this "press" works quite well if you are using a slow-setting adhesive like epoxy. It was described in Fine Woodworking a long time ago.
I have always read the two various opinions on the method for attaching the veneer......contact cement, or iron-on with dried wood glue.
I tried using the contact cement when I originally built my first set of speakers and wasnt impressed with the way the edges turned out, so I thought I would experiment with the other method. With contact cement, it was a little too thick and where the two pieces came together at a corner, you could see a very fine glue line. I applied the contact cement according to the recommendations on the can (two thin dried coats on each surface, and applied pressure with a J-roller). With the wood glue method I am talking about, this glue line is not really visible. It seems to give a better "finished" look along the corners.
I am just looking for some tips and sugestions using this method.
I tried using the contact cement when I originally built my first set of speakers and wasnt impressed with the way the edges turned out, so I thought I would experiment with the other method. With contact cement, it was a little too thick and where the two pieces came together at a corner, you could see a very fine glue line. I applied the contact cement according to the recommendations on the can (two thin dried coats on each surface, and applied pressure with a J-roller). With the wood glue method I am talking about, this glue line is not really visible. It seems to give a better "finished" look along the corners.
I am just looking for some tips and sugestions using this method.
I guess maybe I didn't understand completely your problem. I assumed you meant that you'd iron the veneer then while it was redrying it would curl up. So I suggested weighing it down after you ironed it.
Personally I always use contact cement and a roller as vpharris suggested. But the iron-on method is supposed to work good too. Maybe you're getting the veneer too hot and that is causing it to curl. Try a lower temp setting on your iron or just move it quicker over the veneer.
Personally I always use contact cement and a roller as vpharris suggested. But the iron-on method is supposed to work good too. Maybe you're getting the veneer too hot and that is causing it to curl. Try a lower temp setting on your iron or just move it quicker over the veneer.
I just kinda fell into this thread, but I thought I'd offer the following:
--There was a veneer supplier in Tennessee (Bob Somebody-or-other Woodworking) that supplied large sheets of thermoset glue. Lay it down, put the veneer on top, iron, and you were done instantly. No muss, no fuss, no curling; just cut to size with scissors and go. I don't recall it as being very expensive.
For all I know they took it off the market for causing cancer in laboratory woodworkers.
I've always found contact cement to be a nuisance to work with. Yes, it holds well, but I never managed to get a really even spread no matter how hard I tried. Not the most user friendly product. When I do veneer now, I just do glue and press it. No heat.
Grey
--There was a veneer supplier in Tennessee (Bob Somebody-or-other Woodworking) that supplied large sheets of thermoset glue. Lay it down, put the veneer on top, iron, and you were done instantly. No muss, no fuss, no curling; just cut to size with scissors and go. I don't recall it as being very expensive.
For all I know they took it off the market for causing cancer in laboratory woodworkers.
I've always found contact cement to be a nuisance to work with. Yes, it holds well, but I never managed to get a really even spread no matter how hard I tried. Not the most user friendly product. When I do veneer now, I just do glue and press it. No heat.
Grey
The veneer is not curling due to heat. The glue is applied to the venner and its left to dry. The veneer is curling as the glue is drying. When dry, you use an iron to reactivate the glue and iron it onto the mdf. It sticks instantly, and very well, provided that the mdf and veneer both have a coat of glue. I am trying to either stop the veneer from curling while its drying, or find a way to apply the glue to the mdf only.
If you could offer information as to where to get the "glue sheets", that would be appreciated.
I have also considered using the glue in a press.....no iron, but that seems very time consuming, as only one or two surfaces could be done in a day. Since I only have weekends to work on my projects, It would take me about a month or so, just to apply the veneer. I guess Im just trying to find a quicker way. Maybe I should just order the iron-on veneer from tape-ease.
If you could offer information as to where to get the "glue sheets", that would be appreciated.
I have also considered using the glue in a press.....no iron, but that seems very time consuming, as only one or two surfaces could be done in a day. Since I only have weekends to work on my projects, It would take me about a month or so, just to apply the veneer. I guess Im just trying to find a quicker way. Maybe I should just order the iron-on veneer from tape-ease.
the veneer is curling because it and the substrate have absorbed moisture. When the moisture leaves the cellulose (wood fiber) shrinks back, but not in the way you originally intended. This is why a the 3M adhesive, epoxy or non-PVA are recommended -- especially for large surface areas.
Here is what most likely is happening to your veneer.
The glue that you are using (any glue that is in the same pva family) will allter the moisture balance in the veneer that you are coating. If left to dry and then weighted down and left for a few days to a few weeks (no more than two weeks at worst) The veneer will stay flat. Your application of the glue should be with a small roller. It can be foam or knap standard. Eveness is paramount. Let both surfaces thoroughly dry and especially let the veneer reach a moisture equilibium again and you will have no problems.
How do I know??
15 years of custom woodworking including more veneering than I care to admit to. Your method is good. You just need to understand that wood is alive in the sense that if you change it's moisture content in any way it will expand or contract.
A quick fix for your problem is to wipe the wood side of your veneer with a damp cloth and it will uncurl enough to be easier to work with. Mark
The glue that you are using (any glue that is in the same pva family) will allter the moisture balance in the veneer that you are coating. If left to dry and then weighted down and left for a few days to a few weeks (no more than two weeks at worst) The veneer will stay flat. Your application of the glue should be with a small roller. It can be foam or knap standard. Eveness is paramount. Let both surfaces thoroughly dry and especially let the veneer reach a moisture equilibium again and you will have no problems.
How do I know??
15 years of custom woodworking including more veneering than I care to admit to. Your method is good. You just need to understand that wood is alive in the sense that if you change it's moisture content in any way it will expand or contract.
A quick fix for your problem is to wipe the wood side of your veneer with a damp cloth and it will uncurl enough to be easier to work with. Mark
mwmkravchenko,
I dont think I understand what you mean.....Are you saying I should apply the glue to the veneer and then let it dry. Once dry, I apply weight to flatten it out. When flat, use the iron and apply to the mdf?
Is there a type of glue I should be using that will not cause the curling but I can still use the iron-on method?
Thanks for everybodys help so far,
Jeff
I dont think I understand what you mean.....Are you saying I should apply the glue to the veneer and then let it dry. Once dry, I apply weight to flatten it out. When flat, use the iron and apply to the mdf?
Is there a type of glue I should be using that will not cause the curling but I can still use the iron-on method?
Thanks for everybodys help so far,
Jeff
"Once dry, I apply weight to flatten it out. When flat, use the iron and apply to the mdf?
Is there a type of glue I should be using that will not cause the curling but I can still use the iron-on method?"
Try to keep your veneer flat to begin with. Tape, tack or what ever. There is no heat activated glue that I know of other than hotmelt that you can iron on.
Keep in mind that a good qualtity contact cement bond is only in the order of 200-300 psi shear strength at best. A pva bond under ideal wet conditions is in the 1800 to 2200 psi shear strength region. Even a heat activated bond will well exceed the contact cement.
From a perspective of longevity I have done the most bandaid repairs on the contact cement laminations and none on the PVA work.
Your curl problem is a small price to pay for the ease of ironing on your veneer. THe first time you wrap a loudspeaker from back all the way to the back in one piece you will have appreciated your teething on these small problems.
Such an exercise in veneering with contact cement is DIFFICULT to say the least and I for one have been burned myself by that evil stuff.
A bit of practice and you will be able to veneer curves and the like with ease. It's also fairly easy to remove in comparison with contact cement.
The only thing that is marginaly better is a vacum press a roller, a water mist bottle and polyurethane glue. And yes in that order!!!! And vacum veneering makes your present difficulties look like a walk in the park
Mark
Mark
Is there a type of glue I should be using that will not cause the curling but I can still use the iron-on method?"
Try to keep your veneer flat to begin with. Tape, tack or what ever. There is no heat activated glue that I know of other than hotmelt that you can iron on.
Keep in mind that a good qualtity contact cement bond is only in the order of 200-300 psi shear strength at best. A pva bond under ideal wet conditions is in the 1800 to 2200 psi shear strength region. Even a heat activated bond will well exceed the contact cement.
From a perspective of longevity I have done the most bandaid repairs on the contact cement laminations and none on the PVA work.
Your curl problem is a small price to pay for the ease of ironing on your veneer. THe first time you wrap a loudspeaker from back all the way to the back in one piece you will have appreciated your teething on these small problems.
Such an exercise in veneering with contact cement is DIFFICULT to say the least and I for one have been burned myself by that evil stuff.
A bit of practice and you will be able to veneer curves and the like with ease. It's also fairly easy to remove in comparison with contact cement.
The only thing that is marginaly better is a vacum press a roller, a water mist bottle and polyurethane glue. And yes in that order!!!! And vacum veneering makes your present difficulties look like a walk in the park
Mark
Mark
I have often wondered about using polyurethane, but have been put off by the difficulties caused by the expansion of the glue whilst curing. Most of the vacuum veneer presses I have seen don't seem to be able to provide enough pressure to prevent this.
How did you do this, with what kit, and what were your results like?
I do agree with you about contact cement though, the only thing it is good for is plastic laminates...
Well, my experiment box is getting pretty ugly with all the little pieces stuck all over, but I am starting to get pretty good at this.
When you buy iron-on edgebanding, is the glue that is on that simply hot glue?
Jeff
When you buy iron-on edgebanding, is the glue that is on that simply hot glue?
Jeff
I've always used contact cement. Paint it on both surfaces wait until it's tacking and then press into place. Make sure it goes on straight! If you mis-align things it will impossible to pull back off - I know, I've ruined a whole sheet of veneer doing the speakers below... If you "wrap" a speaker you can end up with only one seam down the middle of the back. To get it straight, before applying the contact cement, use a square to draw a line straight down the center of the back of the speaker. Then apply the veneer with the starting edge exacly on that line. This will make sure it goes on straight as you wrap the veneer around. Use your hand or a round dowel to press the veneer in place and remove air pockets as you wrap. Go slow (contact cement) stays tacking for a long time, and press the veneer on 1" at a time while making sure no air pockets or wrinkles in the veneer are present before continuing to wrap the veneer. Contact cement bonds, well, on CONTACT and is difficult or impossible to break once contact is made. If you leave an air pocket it will be almost impossible to get it out once the next inch or two of veneer has touched and bonded to the cabinet. (one potential fix for an air pocket is to slice it with a razor to let the air out and press it down, but this might be difficult to hide in the finishing stage). Once done wrapping, use a razor knife to cut the veneer out from the speaker hole, binding post, port, and/or other cutouts.
To get a perfect seam down the middle in the back you should start the veneer wrapping 1/4" past the centerline (ie draw another line 1/4" to the right of the center line straight down the back of the cabinet), then wrap all the way around with enough veneer to overlap both where the veneer started, and the center line of the cabinet. Then draw another line on the veneer straight down the center line of the cabinet. Then use a razor knife and straight edge to cut through both layers of veneer (the two layers are because they are overlapped at this point). Once cut, you can lift up the top overlapped veneer layer and peel off the 1/4" strip from below. The top veneer can now be pressed into place with a perfect seam. It sounds more complicated than it is.
The trick is starting the wrap straight - difficult with a large floor standing speaker. Everything else is easy.
That's how I did this one
To get a perfect seam down the middle in the back you should start the veneer wrapping 1/4" past the centerline (ie draw another line 1/4" to the right of the center line straight down the back of the cabinet), then wrap all the way around with enough veneer to overlap both where the veneer started, and the center line of the cabinet. Then draw another line on the veneer straight down the center line of the cabinet. Then use a razor knife and straight edge to cut through both layers of veneer (the two layers are because they are overlapped at this point). Once cut, you can lift up the top overlapped veneer layer and peel off the 1/4" strip from below. The top veneer can now be pressed into place with a perfect seam. It sounds more complicated than it is.
The trick is starting the wrap straight - difficult with a large floor standing speaker. Everything else is easy.
That's how I did this one
Hi Milzie
I read in another post somewhere a suggestion to first shellac (and let that dry) the veneer before applying the PVA glue. The shellac may seal the veneer and therefore prevent the moisture in the PVA from curling the veneer. Give it a go and let us know how your get on. I'm a few steps behind you, having bought some silky oak veneer and currently constructing boxes, so I'll be interested to see how you get on.
Another point worth making is that gluing suggestions seem to vary according to the type of veneer you are using. For paperback veneer contact cement seems to be more commonly suggested, while for plain veneer PVA is more commonly recommended.
Mick
I read in another post somewhere a suggestion to first shellac (and let that dry) the veneer before applying the PVA glue. The shellac may seal the veneer and therefore prevent the moisture in the PVA from curling the veneer. Give it a go and let us know how your get on. I'm a few steps behind you, having bought some silky oak veneer and currently constructing boxes, so I'll be interested to see how you get on.
Another point worth making is that gluing suggestions seem to vary according to the type of veneer you are using. For paperback veneer contact cement seems to be more commonly suggested, while for plain veneer PVA is more commonly recommended.
Mick
Im using plain veneer, no backing.
So far it seems that there is no difference to using contact cement or PVA with an iron. I still need to try clamping the glued veneer to the mdf while the glue is still wet, but I expect similar results. What I am trying to accomplish, is minimize the line where the edges meet, to make it virtually invisible. Glue and iron and contact cement all seem to yeild similar results. I am going to try glue and clamp, and will let you know how that turns out.
Jeff
So far it seems that there is no difference to using contact cement or PVA with an iron. I still need to try clamping the glued veneer to the mdf while the glue is still wet, but I expect similar results. What I am trying to accomplish, is minimize the line where the edges meet, to make it virtually invisible. Glue and iron and contact cement all seem to yeild similar results. I am going to try glue and clamp, and will let you know how that turns out.
Jeff
Could you please tell me what do you call PVA glue? Is that a regular yellow wood glue or something else.
Thank you
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Thank you
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