I'm trying to use the yellow glue, iron-on method for paper-backed veneer. I did 1 coat of Titebond Original (thinned with maybe 10% water) on the box, then 1 on the kraft paper, and let them dry for an hour or so. Then I used an iron (on cotton setting) and an old T-shirt. The veneer seems to adhere all right to the middle of the panels, however at the edges it tends to be loose.
So... I iron over the edges again, then hold a wood block over the edge for 30 seconds or so, hoping that gives the glue some time and pressure to bond. After enough passes at this, the edges seem bonded (how well? Hard to say). The real pickle happens at an edge where the veneer has to "overlap" the veneer on an adjacent panel... it really doesn't want to stick. So I went with 2 coats of glue on the kraft paper; still a real challenge to stick. Again, if I go over it with the iron and wood block enough times, it seems to stick, but I'm not sure how good of a bond it actually is. PLUS, it's taken me 2 days to do a .25 cubic foot box!!!!! @#&$^%
Is there something I'm missing? My next move will be contact cement, pressed on with a "veneer scraper" of some sort.
Come Get Down And Eat Best Food, Sharp. Cee? Sharp.
My next move will be contact cement, pressed on with a "veneer scraper" of some sort.
Unless you have a bagger and can use a Urea based glue, contact cement is your best bet with backed veneer. If all your panels are flat, you could also use a cold press glue and clamp another layer of MDF to it while it sets.
Contact cement, the nasty, non-waterbased kind works great! I used an adhesive roller and a short roller handle to apply the gak to my last project. Works super-great Don't use it inside, though, serious explosion hazard!
I'm trying to use the yellow glue, iron-on method for paper-backed veneer. I did 1 coat of Titebond Original (thinned with maybe 10% water) on the box, then 1 on the kraft paper, and let them dry for an hour or so. Then I used an iron (on cotton setting) and an old T-shirt. The veneer seems to adhere all right to the middle of the panels, however at the edges it tends to be loose.
So... I iron over the edges again, then hold a wood block over the edge for 30 seconds or so, hoping that gives the glue some time and pressure to bond. After enough passes at this, the edges seem bonded (how well? Hard to say). The real pickle happens at an edge where the veneer has to "overlap" the veneer on an adjacent panel... it really doesn't want to stick. So I went with 2 coats of glue on the kraft paper; still a real challenge to stick. Again, if I go over it with the iron and wood block enough times, it seems to stick, but I'm not sure how good of a bond it actually is. PLUS, it's taken me 2 days to do a .25 cubic foot box!!!!! @#&$^%
Is there something I'm missing? My next move will be contact cement, pressed on with a "veneer scraper" of some sort.
I've never had a problem with the iron-on method, but I've always let the glue dry at least 24 hours before ironing.
The major problems I had with iron on came when I only did one coat. I now do two coats of Heat Lock on each surface. I also found using a bit of steam from the iron seemed to tame the curling issue a bit.
Lou's Speaker Site [speakers.lonesaguaro.com] "Different" is objective, "better" is subjective. Taste is not a provable fact. A good speaker is like the right woman, the more you hear, the more you like.
Paul, I used to occasionally have problems as well. These things eliminate problems, though since I went to these all at once, I can't tell you which one is critical.
1) I spread wood filler over the exposed end grain of the MDF, then sand down.
2) I sand the entire MDF surface lightly with 220.
3) I use Heat Lock - I like this much better than yellow glue.
4) I use the glue roller from Veneer Supplies - also a good tool.
5) I thin as you did, but use two coats on each surface.
6) I let the glue dry at least overnight.
1) Ironing too quickly? It takes 5-10 seconds or so to transfer heat to the glue layer. I move the iron about one width in 10 seconds with steady pressure and never completely pausing. I iron an inch in about 2 to 3 seconds using as much pressure as I can muster. (Let's see, that puts a 4 inch wide iron about 8-12 seconds over any one spot.)
2) An iron that doesn't get hot enough? Franklin International recommends 250 degrees with Original glue. That's the supposed "Wool" setting. Cotton should be 350 degrees, but I expect that irons vary wildly. With Cotton, you should be able to move more quickly. Got a thermocouple on your DMM to read the actual temperature? Have another iron to try?
3) Old glue? The glue has a shelf life.
4) Unsmooth but* joints at the edges? Surface prep, like painting, is important or you'll have a "valley" to bridge at joints. I sand the cabinets like I'm getting ready to paint, but with fairly coarse sandpaper (100 grit) to provide "tooth".
5) Oils on the surface of the MDF? Other coatings? I read a US Forestry bulletin once that claimed the strength of yellow glue joints are substantially compromised by existing coatings like shellac, etc.
6) Unwanted oils/coatings on the veneer backing? Same reasons as above.
I hope you can get the problem solved. I've never had any trouble myself.
I've used Bill's method with Titebond II twice now without incident; it's got to be the iron not getting hot enough or old glue like others have said. Once it's stuck and cooling, it ain't going anywhere.
Regarding the overlap on the corners.. as long as the previously glued panel of veneer has been flush trimmed, they should be a non-issue..
Weird. If your iron's getting hot enough, you shouldn't be able to comfortably place your hand on the piece veneered immediately. It should be getting pretty darn hot.
I don't veneer much but, one of the guys who's in the gallery is a veneer guy and has been doing antique repairs for some twenty years. He has explained the yellow glue method to me as such, coat both sides with unthinned and allow to dry just past tack. Align the sheet and roll out.
Very, very good suggestions, guys. You hit on a lot of stuff I hadn't thought of.
First off, maybe the heat lock is just better stuff. This is not my first attempt with iron-on yellow glue (my first try was a year ago with wood-backed veneer... very similar results).
The glue is not old (to my knowledge). I just bought it from Home Depot last week.
I didn't realize you were all doing 2 coats on each surface. I'll do that.
By the way, Bill, your page is my guide here. I have it linked on my web site.
And if the next box takes as long, then I'll go buy a can of contact cement for the rest of the project.
Come Get Down And Eat Best Food, Sharp. Cee? Sharp.
Many more experienced people than me have been responding.
All I can say is that the iron-on method is working pretty well for me with heatlock glue and a veneer roller. I've been pressing pretty hard with the iron and going slow.
At Joe's suggestion (from joewoodworker.com/veneersupplies.com), I've also been giving a light spritz with veneer softener prior to ironing.
Paul,
One thing that helped me a bunch:
After I had ironed all the veneer on I went back and checked all the edges. If I found a loose edge I just shot a little thinned glue under it using a very small syringe. Then hit just that spot with the iron. You can get the syringes at pretty much any pharmacy, we had a bunch left over from a diabetic cat of my wife's.
I've used Bill's method with Titebond II twice now without incident; it's got to be the iron not getting hot enough or old glue like others have said. Once it's stuck and cooling, it ain't going anywhere.
Regarding the overlap on the corners.. as long as the previously glued panel of veneer has been flush trimmed, they should be a non-issue..
Weird. If your iron's getting hot enough, you shouldn't be able to comfortably place your hand on the piece veneered immediately. It should be getting pretty darn hot.
I never had much luck with the wood glue/iron method. One speaker project I did had rectangular boxes that were done with iron and glue, paired with ribbons in a curved baffle done with contact cement. After 10 or so years and multiple moves, the curved baffles with contact cement are perfect, the boxes have numerous separations and flaked off veneer, and at the time I thought everything was tightly bonded. This last build I didn't try the iron/glue but went instead to contact cement from Joe Woodworker/Veneer supplies website called Titan. It has virtually no ordor and cleans up with water, appearance is like white glue but a little thinner. Grip seems tenacious, its easy to apply. I'm assuming it will hold up, and I'm quite pleased with it. The only trick is to apply the veneer without accidentally touching it to a surface where you don't want it bonded, because it is instant. You can then instantly proceed to finishing which is nice.
I use Titebond II slightly thinned, NBL veneer and put 2 coats on each surface. I use an old Black & Decker iron set on high. I start in the middle of a panel and work my way out going slow and applying pressure. I tap the surface all over with my finger to listen for loose spots and reheat any until they stick. If I end up with a bubble that's stubborn I pierce the veneer with the tip of and Exacto knife and iron around the hole until the bubble is gone. As I trim the veneer I rub my finger up across the joint to see if any edges are loose. You can hear it if it is and iron it down.
All of the speakers I have in the Speaker Project Gallery except the set in Mahogany were done this way.
I've had good luck with both Titebond and Titebond II.
From my experience, getting enough glue was a big thing, had bubbles and loosining edges until I went to 2 layers of glue on both sides. Even application is important, I got a tip to use a piece of 24 tpi hacksaw blade as a spreader, the teeth make it easy to get an even, consistent layer.
I've let it dry some hours to overnight or longer.
Enough heat is important too, I usually set it to Cotton, and use a t-shirt around the iron to buffer it. I go slow with pressure and another tip I heard seems to help, using a block of wood in my other hand to follow the iron. This continues the pressure on the just heated section, as well as sucking the heat out faster and hopefully setting the glue better before it can move.
Level edges might be something important I hadn't thought about, I typically "lap sand" my box faces with a sanding board made from a cut 6"x48" sanding belt. It's a 12"x24" sanding surface, sliding the faces over it makes the edges close to perfect, so maybe I haven't had the uneven edge problem Bill mentions.
Lastly, I usually use a layer of shellac as a sanding sealer on the MDF or underlying surface, and haven't noticed problems with glue adhesion.
Hope that helps...
Originally Posted by williamrschneider
1) Ironing too quickly? It takes 5-10 seconds or so to transfer heat to the glue layer. I move the iron about one width in 10 seconds with steady pressure and never completely pausing. I iron an inch in about 2 to 3 seconds using as much pressure as I can muster. (Let's see, that puts a 4 inch wide iron about 8-12 seconds over any one spot.)
2) An iron that doesn't get hot enough? Franklin International recommends 250 degrees with Original glue. That's the supposed "Wool" setting. Cotton should be 350 degrees, but I expect that irons vary wildly. With Cotton, you should be able to move more quickly. Got a thermocouple on your DMM to read the actual temperature? Have another iron to try?
3) Old glue? The glue has a shelf life.
4) Unsmooth but* joints at the edges? Surface prep, like painting, is important or you'll have a "valley" to bridge at joints. I sand the cabinets like I'm getting ready to paint, but with fairly coarse sandpaper (100 grit) to provide "tooth".
5) Oils on the surface of the MDF? Other coatings? I read a US Forestry bulletin once that claimed the strength of yellow glue joints are substantially compromised by existing coatings like shellac, etc.
6) Unwanted oils/coatings on the veneer backing? Same reasons as above.
I hope you can get the problem solved. I've never had any trouble myself.
Paul, judging from your description of your problems, I'm thinking that the iron just isn't getting quite hot enough.
I usually just put one fairly thick coat of Heatlock on both sides, and maybe touch up any places where it absorbed into the wood. I haven't used yellow wood glue yet, since I've had no issues with Heatlock.
Then I wait the recommended amount of time, which for Heatlock is only an hour or so? I can't remember, but it's not too long. Just until it's not tacky to the touch.
Then I use the iron at the highest setting with an old cotton t-shirt under. With the T-shirt and the fact that you are constantly moving the iron, there shouldn't be any burning or searing issues with the veneer.
Really, I think your iron just isn't getting hot enough, or you just need to turn it up to full and do some test strips. Like William said, as much pressure as you can safely generate with a plastic-handled iron is good.
I also think that the iron doesn't get hot enough.
While I haven't attempted serious driver measurements, I can still contribute some data to the common good. I found my thermocouple and heated up my old '80s Proctor Silex (made in USA!) iron to see how hot it got.
I've included a chart of the temperatures I found. Note that I couldn't use my iron's setting number 6 because the plastic dial reached its stops at 5. The last time I veneered, I used setting 4 (Wool) and it worked fine.
I also found that the iron cycled about 50 F from the peak to where it drifted before the element cycled again. I included that range in my chart shown below.
Last edited by williamrschneider; 06-16-2010 at 03:25 PM.
Bill Schneider
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I'm no pro, but I found the iron/glue method to be much more satisfying than painting (on my first try...full-sized Statements). I was pretty intimidated by the size of the veneer sheets (one 4' x 5' sheet just to wrap around the front and sides).
I used Titebond II. I put on a really thick coat using a foam roller (poured the Titebond II right out of the gallon jug onto the veneer and speaker cabinet). Thick...it took a few hours to dry enough to do the ironing. I used a fan and a halogen lamp at one point to help with the drying. There are only a few hours of time after it has dried where you can 'reactivate' the glue by ironing (12 hours with Titebond II...http://www.webherrera.com/blog/2009/...-instructions/)
I protected the veneer from the iron (hottest setting) with a sheet of paper (11" x 17") rather than a cloth or T-shirt. I figured paper would be less of a thernal insulator. I went SLOWLY, making sure every area got plenty of iron time. Iron in my right hand and a piece of MDF (approx. 12" x 8" x 3/4" thick) in my left hand, pressing down on the area I just ironed (applied LOTS of pressure with the MDF and the iron).
Caution with a lot of heat: I noticed afterward, when trimming some edges and speaker holes (where the veneer is not backed by any MDF) that I burned the glue in some places. I probably went too slowly...but the veneer is still fine after 9 months.
I hope things work out better on your next try with the veneering.
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Veneer Frustrations
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Re: Veneer Frustrations
Originally Posted by Paul Carmody
Don't use it inside, though, serious explosion hazard!
