Veneering rounded edges

[tktran]

Hi,

I've had excellent results in the past with applying timber veneer on MDF, Pete Mazz style (coat veneer and substrate with PVA glue, and wait approx half hour til dry, then align, apply pressure and iron on) but always on a loudspeaker cabinet with square edges. This has worked great for 2 different floorstanders, one with raw veneer, and the other with paper backed veneer.

Has anyone used this method, or any other method, for applying veneer to a baffle whose sides have 1/2" roundovers?

How well does veneer bend around these edges, and how well does it stick using the iron-on method?

best regards,
Thanh.

[PoorboyMike]

I'm trying to veneer an octogon shaped sub right now using the iron on method. It went around the corners ok but it doesn't want to stay down about 1/4" to either side. It doesn't look bad but when you run your hand down it you can hear a cracklin sound. If I can't get it figured out I'm going to have to peel it off and start over. If that happens, I'm going to use contact cement. It kind of sucks because I'm going to have to buy more veneer now. :cry:

[tktran]

An octagon shaped sub sound interesting- does that mean that you are attempting to bend your veneer around sharp edges?

I've had that crackling sound before, and it is the sound of the veneer not not properly applied.

You may need to re-heat with the iron, and work over the crackly bit using more pressure, stroking in one direction, over and over (patience +++). As you turn off the iron and the veneer is cooling, keep ironing to ensure that the veneer doesn't lift.

[PoorboyMike]

Yeah, I just got the outside a little damp with a wet rag and it folded right around.

I'll try doing what you said when I get home tonight. Maybe I'm just not being patient enough?

What temp do you set your iron on? I have mine on the cottom setting but I think it might be too hot?

[tktran]

I have mine on the cotton setting too. I usually put a thin cotton sheet over the veneer, and iron that, instead of the veneer directly.

Some of these things like iron temperature, amount of glue to use, need a bit of tweaking, depending on your iron, glue, veneer type etc, but as always, I always do a test run on some off-cuts of MDF.

But I've got a funny feeling with these roundovers. If I buy a 8x4' sheet of bird's eye maple, poplar burl or other expensive (and non-sustainable!) veener, I will only ruin it and have to throw it away, all because I wanted to push it with my iron around some curved edges.

[Hank]

I always do 3/4" roundovers. If you use the veneers you described, I recommend veneer softener. Apply to the veneer roundover areas.

[cjd]

1/2" is on the small side. Pick your grain pattern carefully.

You can consider steam-bending or similar too (place a wet rag along the bend line and iron till it's steaming through - you *may* be able to do this with the PVA already in place, not sure).

[Dennis H]

I think 1/2" is pushing it with burls. Tapeease recommends 3/4" with the grain (grain runs up and down, wrap side to side) and 3" across the grain. But burls don't really have any grain direction so it's all wrapping across the grain. Better practice on some scrap first.

About keeping it stuck down, try the two handed trick with a hot iron and a cold iron. Follow right after the hot one with the cold one to keep the veneer pressed down while the iron sucks the heat out and the glue hardens.

[augerpro]

I'll second what hank said about the softener. I used the stuff from joewoodworker. I applied the softener and premolded the veneer around the roundover. After it dried I spritzed just a bit to make sure it didn't crack, then applied glue and ironed it on. Worked great on the 1/2" roundover.

[Brian Bunge]

Even with a 3/4" roundover the 10-mil paperbacked birdseye maple I used wanted to crack a bit. I took things really slow and any cracking was minimal. The customer never said a word about it so I am assuming things never got any worse.

[JonP]

About keeping it stuck down, try the two handed trick with a hot iron and a cold iron. Follow right after the hot one with the cold one to keep the veneer pressed down while the iron sucks the heat out and the glue hardens.

I've heard that Jon uses this method... great idea. In my limited veneering experience I've done something similar, I get a rectangular, hand sized piece of MDF, round the edges slightly, and follow where I've been ironing with it. It provides the pressure as well as the heat sinking effect. (not as good a cold iron though!) Turning the piece occasionally helps with the heat sinking, keep flipping it and you have a cooler "press" surface.

If/when I do a really large box project, I'll be getting that second iron...

I should mention that I'm in progress with veneering the pair of wedding present Modula MT's that have been waiting for me to get less busy... they have 3/4" roundovers on the sides of the front baffle, so I'm about to get some direct experience on the thread topic. Veneer is a fairly flexable paper backed African Mahogony, not a big challenge there.

[tmorton]

Vacuum Press Pros and Cons

I have been doing quite a bit of reading on veneer lately as I am in the process of tackling my first project. Something that I do not hear or read much about is the use of a vacuum press. Does this typically not work as well or is it a cost / space problem for doing large speakers? I found a very interesting DIY vacuum press that could not only be used to apply veneer but also possibly used for gluing my statements together. Am I missing something here because it seems like this method could be quite useful but I am still very much a noob.

Link to DIY vacuum press.
Joe Woodworker Vacuum Press

Ty

[cjd]

It's a size thing. And a quantity thing. The investment in a vacuum press suggests you'll likely use it a lot. If so, great. But if not...

This is why I like the bigger roundovers! 1" or 1.5" - no smaller than .75"

Of course, so far I've not veneered at all, just stained the raw birch ply. Or not stained.

[JonP]

A vac press would be very cool... but there's a fundamental problem with boxes. You create 14.7 PSI on every square inch of the surface, what happens to your box with that kind of pressure? You might hear a loud BANG from the garage, and find a bunch of shattered pieces sticking out of your now deflated vac bag. :E

I've heard that some folks have been able to pull off putting another bag inside the box, with a hose out to atmospheric pressure, now you have a inner bag pressing with equal force and you then won't implode. If you have a complex interior, like with braces, and the forces don't evenly spread, it might not work.

It might be eaiser to veneer the flat pieces, then do the box assembly.

And to cjd... I'm a fan of a good looking piece of BB... had some with nice grain figure on top, and I think the layers look cool when roundovered. The Modula's I'm working on as a wedding present were built that way.

Unfortunately, the "customers" expressed a preference to a darker wood, so they are being veneered. After the driver cutouts have been made. With a Jasper, so there's no hope of re rabbeting the flush mount steps with the bit that made them :rf
I'm getting a pain in the posterior lesson in why one does it in the opposite order. Ah well, some creative problem solving practice..

[cjd]

This isn't dark enough? :P

[dlneubec]

Personal opinion here and probably not one in the majority, but I really don't care for the rounded over verneer look.

To me it screams "this is a thin layer of wood or plastic veneer" not real wood. Real wood would have seams and changes in grain at the edges. I like something that looks like it was made out of real, high quality hardwood, whenever possible.

YMMV. :W

[JonP]

This isn't dark enough? :P

Heh....

Well, it was more of a middle shade wanted, more able to match future decor, than a very blond Birch. And, I kinda wanted to use a nicer wood, so I did some leaning in that direction myself, and have me to blame as well... ops: Still, I liked the contrast of the black RS drivers and the very light wood.

Anyway, the middle brown African Mahogony will fit in with a lot of things, whether it would look better with a black baffle or not..

On my opening the veneered holes situation, I thought I was on to something with the tiny sanding drums for the Dremel. I found a washer to fit on the end as a bearing surface, and spent some time grinding it down to just larger than the drum. Still, the screw holding it down stuck out too far, even with some grinding down, so it was a wash. Maybe with a thinner washer.... I finally broke down and used one of the cutting bits, got real close by hand, and used the sanding drum to carefully flush the veneer edge. Not as bad as I thought, but time consuming. Many passes needed, etc. I should mention I have the plastic "router base" thing for the Dremel, would be much trickier to do completely freehand.

[JonP]

A later update on my results with the ironing and 3/4"...

I did have a few areas that didn't fully bond, and extra ironing was needed. Some edges, and a fair amount of the roundover areas needed extra attention.
I didn't notice some of these till the next day or so. Let them sit and re absorb moisture in the air after being dried by the iron heat, and you'll find any bubbles by running your fingers over them, and pulling on edges.

Another maxim of iron on gluing is proved... "When you think you have just enough glue, put on another layer"

I also did have the slightest of cracks on one of the roundovers, where I might have glued both edges first, and worked to the center. Bad idea. For the least stress on the veneer, it would look like starting at one corner, then working up one edge, then working across from there to the opposite edge would be best. The remaining 3 roundovers I did that way, and had no problem, YMMV...