Ironing on Veneer question

[JonP]

Finally, a 3 day weekend, and one not totally occupied with other commitments...

Hoping there's a few iron on veterans out there. I know Jon was doing some long pressing with the M8ta's....

I got myself some nice African Mahogony veneer, and I'm planning on the iron on-yellow wood glue method. I'm also planning on using a long, single piece to wrap around the front and both sides of the Modula MT boxes. I have the front baffle sides rounded with a 3/4 roundover.

My concern, is how much shrinkage might I expect, with a long piece like that? I've read that pre ironing can handle some of it. Any suggestions on how to iron to minimize stress and cracking, or does it matter that much? The grain is going vertically, i.e. from the top to bottom of the box.

I have done this once before, and it worked well, but that was on a pair of tiny boxes that were barely 8"x9" on their widest side.

I'm kind of close with the half sheet I bought, so I dont have a lot to spare for test pieces...

[bob barkto]

Is it backed or raw veneer?

[JonP]

This stuff is paper backed... not sure of the thickness, it's pretty thin and flexable.

I've only had experience with some thicker, unbacked Pommelle Sapele... it was thicker, very wavy and unbacked. It shrank visibly when I pre ironed it, and wanted to curl up quite a bit when the glue was applied.

[bob barkto]

I think you'll do fine with backed veneer. The backing really helps prevent the veneer from taking up too much moisture, which is the cause of problems with unbacked veneer. Raw (unbacked) veneer is miserable in comparrison.

You should get very minimal shrinkage compared to raw veneer. Pre-ironing a small section should show how much for the piece of wood you have. Any cracking/buckling/bubbling should be minimal or non-existant as well.

Here is how I approach it.

After applying the glue, wait... as long as is practical. Overnight - 24 hrs. is about right. Most of the moisture will evaporate so you'll have minimum shrinkage.

I'd start ironing down the front/center, less than the width of your iron, and work outward a few inches to each side of center at a time. Continue that way across the front, around the sides and work your way to the back.
It can help to pre-heat the veneer just ahead of your pressing down passes.

It might be helpful to tape the veneer loosely in place to help keep things square.

[Brian Bunge]

I've found I much prefer Titebond II vs. the original Titebond. It seems to spread easier and dry faster and doesn't cause the veneer to curl up as much. It also seems to re-activate much easier.

I always cut the veneer 1/2" to 1" oversized so that I have room for error when I wrap the veneer around the cabinet. So I haven't noticed any real issues with shrinkage.

[bob barkto]

Shrinkage is more of a concern in regards to cracking, checking and splitting.
It is a real major problem with unbacked veneer. Sometimes the cracks develop hours or days later. Sometimes instantly.
With backed veneer not so much, if at all.

Your glue experience is interesting.
I also expereince less curl with the TB2. But I've had slightly better overall results with the original TB. It did need more coats/heavier spread tho. Overall the differences are minor IMO. Either gets the job done in the end.

I've found I much prefer Titebond II vs. the original Titebond. It seems to spread easier and dry faster and doesn't cause the veneer to curl up as much. It also seems to re-activate much easier.

I always cut the veneer 1/2" to 1" oversized so that I have room for error when I wrap the veneer around the cabinet. So I haven't noticed any real issues with shrinkage.

[JonP]

Thanks guys....

OK, pretty much common sense stuff, as I'd hoped. Had some fears that not ironing a certain way would cause splitting, sounds like it's much less of an effect (on this kind of veneer) as I thought.

I'm debating on getting a bottle of Titebond II, have a bunch of I, maybe I will maybe not. I might do a small sample to see the curling effect, which sounds like it's a lot smaller on the paperbacked rather than raw.

I did get some milage done, got front baffles glued, will get the permenent crossover mounting done, then the backs go on with their new back brace piece, and it's sand and fill and smooth for the veneer.

Found it a bit difficult to take them apart, since I'd been enjoying them, they were all sanded out and square in their bare BB glory... dammit, they were FINISHED!!! and now, they are slightly off again, and all apart.

But, they will look so much better with the Mahogony on, and REALLY finished.
Sigh, then I give them away to my Sis and her new husband... and, on to the next project!

Any other practical tips and hints for the remainder of prep, filling and so forth?

[Martyn]

Any other practical tips and hints for the remainder of prep, filling and so forth?

You'll probably want to "stain" the finished box. Mahogany takes a dye better than a stain, but I suggest that you apply any scraps of veneer to some MDF or plywood and use them as test pieces. Start with a weak dye solution - it's easier to apply another coat than to remove one! Use the same test pieces to test your grain filler (if you want to use one) and your chosen finish. You should really work through all these steps before finalising your choices, because each step will change the final colour to some extent.

[JonW]

If I could revive this old thread...

I've not yet tried the iron-on veneer method, but I will with my ongoing project. Two pretty easy questions for you veneer experts:

-How long after ironing should you wait before trimming the extra veneer off the edges? Is it OK once it cools or should you wait overnight?

-How best to trim the extra veneer off the edges of the cabinet? I'm building a cabinet with facets, so I can't simply use a flush mount router bit. On my Modula MT's I tried using a straight edge utility knife with fresh blades. It came out OK, but not great. For the facets I was thinking about trying a veneer saw:

http://www.veneersupplies.com/product_info.php?products_id=609

Any opinions for trimming?

[Bill Schneider]

I can't answer the question about how to trim facets, but I did some experimenting with various bits for rectangular boxes. I've put together a web page explaining the process and the results of my veneering experiments.

I've trimmed my veneer within 10 minutes of adhering it.

I'm not the most experienced woodworker, but these notes should help someone get started...

http://oak.cats.ohiou.edu/~schneidw/audio/veneering.html

Bill Schneider

[stangbat]

I can't answer the question about how to trim facets, but I did some experimenting with various bits for rectangular boxes. I've put together a web page explaining the process and the results of my veneering experiments.

I've trimmed my veneer within 10 minutes of adhering it.

I'm not the most experienced woodworker, but these notes should help someone get started...

http://oak.cats.ohiou.edu/~schneidw/audio/veneering.html

Bill Schneider

That is a great guide. I'll be veneering some speakers for the first time and I'm going to use the iron-on method. You've saved me some frustration, I'm sure. Thanks a ton.

[Dennis H]

Yeah, a veneer saw is the best bet for trimming facets. Put on a strip of masking tape to run the saw against, both to keep from scratching the veneer already in place and to leave the cut a bit 'proud.' Then sand the last little bit of the edge off with fine sandpaper on a flat wooden block so you get a nice edge. Practice is your friend before you muck up your nice cabinets.

[JonP]

Wow... a blast from the past...

Kind of weird to see a subject title, go to offer some possible advice.. and find it's your own thread from a while ago!

And, embarrassing in that it's been that long, and they've only been finished a month or two.. ops:

So... I did use the Titebond II, seemed slightly better, but hard to say how much. Not a big difference, as Brian and Bob said... It went very well, the veneer was very flexible, no problems doing a full wrap side-front-side around the 3/4" roundovers.

Another thing that seems to help, and I think this is a Jon Marsh trick, is to follow the iron with a block of MDF (big jobs, he uses another cool iron!) to press down on the just heated area, as you move along. It holds pressure while it's cooling, and helps to cool it a bit faster.

Yep, when the glue is cool, its hard... It's a good thing to let it sit for a while, I'd guess there's a bit of re-absorbtion of moisture from the air, and very minor expansion of the veneer. Time should be spent right after, checking for bubbles and loose spots by rubbing your fingertips over the box and gently pulling at edges. You'll hear the hollow sound of a lifted area, or see it come loose with the pulling, and then you want to go over the areas again with the iron till they're solid. I ended up with just a few spots that needed going over again.

Ah, how I trimmed... After getting splits and tearouts even with a sharp Xacto on the Bubinga... I ended up using my flush trim bit and the router! Not as scary as it sounds.. I did a layer of easy release tape to protect from the bearing, and that did provide a few thou of overhang... then sand to flush. Only problem, be CAREFUL in removing the tape! I actually pulled up some grain, even with the blue easy release painter's tape! ARRRGH! Always pull it off ACROSS the grain, not with... Your wood may vary... but it's less likely to come up that way.

Somehow, I never got to staining the veneer. I started with a coat or two of Zinnser's Seal Coat.. it's a moderate amber Shellac... and it darkened it a fair amount. I just started putting on coats, and after many umpteen layers, it turned out very nice! Takes forever to build, and I probably should have done it with poly... but oh well...

Soon they go to my Sis and Bro in Law... still not late enough to be the 1st anniversary present!! :roll:

Bunch of pics in my Photo-bucket... still have a few more to put up in the near future... Also one shot of the veneered 3" PVC support in the stand... that turned out very nice too...


And here's one, for those who read this far... :W

[Hank]

JonP, very nice work! Beautiful grain. :T

[JonW]

I'm glad I asked about the veneering. Some very good tips here.

Bill,

Super web site. Thanks!


Jon,

Good advice. That’s all helpful for me. And your Modula MT’s look pretty slick from the photo. The grain is quite nice.

Yeah, a veneer saw is the best bet for trimming facets. Put on a strip of masking tape to run the saw against, both to keep from scratching the veneer already in place and to leave the cut a bit 'proud.' Then sand the last little bit of the edge off with fine sandpaper on a flat wooden block so you get a nice edge. Practice is your friend before you muck up your nice cabinets.

Excellent tip about adding the tape there. I'll definitely try that. Thanks.

[technimac]

Wow... a blast from the past...
Ah, how I trimmed... I ended up using my flush trim bit and the router! Not as scary as it sounds.. I did a layer of easy release tape to protect from the bearing, and that did provide a few thou of overhang... then sand to flush. Only problem, be CAREFUL in removing the tape! I actually pulled up some grain, even with the blue easy release painter's tape! ARRRGH! Always pull it off ACROSS the grain, not with... Your wood may vary... but it's less likely to come up that way.

:agree:
That's exactly the method I used on my MT's and it worked very well. :T
Highly recommended!

The veneer I used was raw, heavy-flaked white oak. I first tried the PVA glue/iron-on route and after a losing battle with curling and shrinkage, I ended up using polyurethane glue and a press.

Here's how I did it:

https://www.htguide.com/forum/showpost.php?p=294704&postcount=19

And the finished look.


HTH, Bruce

[cacophonix]

Beautiful, Technimac!
Your work rivals that of professionals! ;x(

[james5]

Technimac...what paint/method (rattle can, brush, roller) did you use on your baffle? Great looking speakers!