Wet gluing veneer

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I've read a lot about how to veneer with contact cement or by applying wood glue and ironing on. I've also heard that vaccuum clamping is much better than these methods and I'm pretty certain that wet glue is used in this technique, as opposed to the iron-on method.

Question-if I can apply 1000lb/ft^2 of clamping force, can I just wet glue the veneer? My plan would be to use NBL or 2-ply veneer (not thin paper backed), a layer of wax paper, and then a panel to spread the clamping force. Since bubbling seems to be a problem with the other techniques, I'm hoping that this would solve that problem.

Is there a reason not to do this?
 
Clamping a veneer project in cauls works well IF the pressure is spread evenly. This means clamping cauls significantly beefier than a sheet of mdf.

I made a test 12x 12 panel using my workbench's 2" top as one caul and a piece of mdf braced with a 2x4 laid on its wide face. I honked pipe clamps down as hard as I could on the 2x4 and a couple spots on the edges and still got wrinkles in the surface. I remember seeing a veneer press somewhere with 2x4s on edge about 6" apart and 6x6 timbers 6" apart across that to take the clamp load. Probably overkill, but it gives you the idea what it takes to keep the caul flat against the veneer and substrate.

A bottle jack in the center of a well braced caul pusing up against a beam (not just a joist) would probably give better results than clamping around the edges.

I have used the iron on method successfully, even around 1.25" radius corners. It worked the first time I tried it! I got a small bubble at the seam while the finish was drying - walnut in direct sun. I ironed it back down and it's been fine since (although kept out of direct sun). Just be sure to get enough glue on each surface, but not so much that it leaves lumps. You can iron out lumps to a degree, but it is easier without. Start in the middle and work your way out. Also be careful not to get glue on the good face of your veneer when you are putting glue near the edges. (says he too knowingly :()

Some people swear by contact cement, but I haven't tried it for veneer because I prefer a lacquer finish, which isn't compatible with many contact cements. I had enough trouble with it using vinyl and formica type products that I probably won't try it.

A vacuum press will give about twice the clamping pressure that you propose to use, and it will be evenly spread by a less substantial caul. I'm building a vacuum press now.
 
Bob, nearby all of those users (on the Visaton bord), who apply veneer on their speakers, are using the method with is linked in my original post on the Visaton board.
This method is in "our" point- of- view the "ultimate" guide to veneer speakers...

I can't understand, why You got wrinkles while using clamps...
You are the first one who tells me that...
This is nearby impossible...

Did You have a look on MrWoofa's website?
If not, try...

The most common way to veneer "wet" is:

| MDF (25 mm / 1")
| Veneer
| White glue
v MDF (19 mm / 0,8")
 
Thank you both for your info. The local hardware store has some very large hardwood discards, maybe I'll look into laminating a piece onto MDF to make a stiffer caul.

A bottle jack in the center of a well braced caul pusing up against a beam (not just a joist) would probably give better results than clamping around the edges.
I like this a lot, unfortunately, I'm also quite sure of my wife's reaction to it.
 
Benny the 2. said:

I can't understand, why You got wrinkles while using clamps...
You are the first one who tells me that...
This is nearby impossible...

Did You have a look on MrWoofa's website?


When I saw German, I figured I'd have my son translate tonight, but remembered that i can let google do the translation. Nice tutorial, even though google's german vocabulay is limited. I see you use a modified iron on on the chamfers. It would be difficult to use that method to wrap a continuous piece of veneer around rounded edges, since you'd need curved cauls. Vacuum pressing and iron on would work well.

I guess my clamping board was not flat and/or my edge clamping may have contibuted to losing pressure in the center since the caul board was wider than the test piece. trying for overkill, I just messed it up, I guess.

tiroth said:
I like this a lot, unfortunately, I'm also quite sure of my wife's reaction to it.

do it in the garage or basement when she's out shopping - you only need a couple hours in the press ;)
 
The quick answer to your question is yes, but do a test piece first.

There are many variables involved with wet-gluing veneers and the ability to handle them in in your shop with your tools.

Not the least of which is how each particular veneer reacts to the type of adhesive you use, combined with your pressing technique. Here is yet another link to articles and advice on veneering

Bubbling can be a product of not pressing them out as you roll it, (some people prefer a hard edge rather than a roller) or movement of the wood as the glue dries. Water causes wood to swell, some more than others and even some areas more, in highly figured sheets. Many will say failures with contact cement are likely, but it's my preferred method (I use PVA at joints only)as I don't like to deal with the mess, bleed-thru or the curling for small projects. I've been working with wood and doing veneers and laminates for 30plus years and its possible something I do right, is missing in the technique of those with cc failures.

We all have our experiences with successes and failures with veneers, you can read a thousand of them and get some tips, but still your set-up will be unique. My advice is to jump right in with your best educated guess with your abilities and tools and take your time on each step. The cool part of working with wood is that everything is fixable.
 
start flat, stay flat

Tyler,
If you opt for the "wet" process, consider your glue-up assembly as a "sandwich". Every layer of the sandwich needs to smooth and flat. If you clamp to a work bench, the surface must be flat. If you use a hydraulic jack as a press, the floor must be free from bumps. Be watchful of distortions caused by misalignment of clamps and cauls.
Bubbling in this method is due largely to trapped air. Use a glue spreader to apply glue to both surfaces. You can use some time with a roller to push the air out. Lastly, do a dry run. Nothing is so frustrating during glue-up as to realize I forgot something, it is out of reach, something moved or spilled unexpectedly ya da ya da ya da. Plan and check will minimize the dreaded arched eyebrow of the spouse.
Hope this helps.

whateryabuildin' by the way?
 
Ultimately, I want to build final boxes and veneer my Aurum Cantus / PR170M0 / HM170Z0 project. Since I've never done this before though my first attempt is on some simpler dipole home theatre boxes using those 18cm Vifa/Infinity drivers, AP130M0, and planar tweeters pulled from Monsoon PC speakers. I won't be as upset to make some mistakes here. ;)
 
Buy an inexpensive vacuum pressing kit. Can be had for about $300 or less fromonline vendors. If you build your project and decide you don't want to build anymore just list it for sale here and someone will surely buy it. Even if you sell for -$100 retail you will still have great speakers for $100. This beats the heck out of clamping.

An externally hosted image should be here but it was not working when we last tested it.


christof
 
DO NOT USE CONTACT CEMENT IN A VACUME PRESS!!!!!

THe two types of glue that work in a vacume press are yellow carpenters glue and ployurethane glue. They are both rolled on in a thin layer on both surfaces and then the stuff set inside a "clamped". It can be done by novice. Heck I was a novice 10 years ago. and my first job worked out well. I did a lot of dry clamping to figure out how it would react. I reccomend the same. If you want some tips on making a bag give me an email.

Mark
 
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