Had a first attempt today at hammer veneering. This is a thing that i have wanted to do for a long time and have several projects that it will be usefull for.
Made a veneer hammer, mixed glue and sawed weneer, 2mm thick. My shop is about 8 degrees celcius but heated all parts at the stove right before veneering
Wanted to lay several strips down parralel and made this test pieze on mdf:
As can be seen here the adhesion was not as good as expected. Allso the veneers bowed upwards at the edges despite putting glue on both sides. Tryed reheating with a heat gun (had no iron in the shop) but to no better result.
Now what am i doing wrong?
As i see it there are several factors:
- Glue temperature (was about 70 celius)
- Glue too thick/thin?
- Veneer too thick (1,6mm)?
- Shop too cold?
- Not enoug/too much pressure?
- Glue too old? (did the tack test between fingers and it did get tacky and made small strings)
Your glue is on the warm side but still in range, especially in a cool shop so that shouldn't be the problem.
Veneer thickness should not be a problem unless it wasn't flat.
Shop too cold could be part of it depending on how fast you were.
No such thing as too much pressure but not enough could be contributing.
If your glue strings it is fine.
So …... my guess is what I think most people do wrong at first. I'm guessing your glue was too thick. Thinner glue holds the heat better, squeezes out more easily, and penetrates better. Try a little thinner and see if it helps.
-You might also try moistening both substrate and veneer first.(water)
- Did you tooth the MDF?
- Definitely get an iron. It allows you to apply heat and pressure at the same time.
Do not own a tooting plane but sanded the mdf with rough sandpaper. Do you think that will do?
Applyed A LOT of pressure…
I guess thetemperature is against me. Perhaps veneering is more of a summer thing- unless of course i work inside the house. Not sure thet will be rezieved well with the smell of the glue…
Thinner glue seems counterintuitive and would not be my first guess. That is why this place is such a great place for information.
Will try thinner glue and premoistened weneers and see how that goes. I want to learn to master this thing!
Thanks again
Hey it worked!
Went straight out and tryed your suggesttions and it went perfectly well. Great.
Now i am getting ambitiious and want to mage a panel with heering bone pattern with a lot of strips of veneer. Are there anything special that i need to take into consideration before doing larger projects like this?
Not much if it is lots of small pieces. Large single pieces require some planning and present cooling problems but a large area covered with small pieces should be within your present ability…... and you will get better quickly.
I did a video a while back where I did a lot of strips. I jointed them first and worked them together with the hammer.
You can also overlap and cut both but for thick veneer like you are using I would suggest jointing.
Here's the video: http://lumberjocks.com/shipwright/blog/36014
Super usefull video, Paul, thanks!
A few hours after writing above post about it working perfectly well the veneer losened again. Damm! After close inspection it was ovious that top fibers in the MDF had loosened or the glus dissolved and the veneer came off. Guess this technique needs better quality mdf or perhaps plywood..
Mads: Thanks - try to share. In the end i gave up and experimented with using a vacuum bag made for storage of clothes and it worked perfect. The resulting board is now a shelf at the side of my bed.
Glad you got it sorted, I like hammer veneering, and also struggled with the same too thick of glue the first time or two until I got it figured out. That was going to be my suggestion until I saw that Paul also suggested it (a far better resource on veneering than I).
Thanks Mos!
I consider hammer veneering a basic and vital ww-ing technique that i just need to know how to do. So have not given up yet. That said there is surprizing little information on the subject on the net and in books so my research continues. What kind of projects have you done with veneer?
I have found that MDF is a poor base for hide glues. The main reason is that it takes one of hide glue's best features out of the picture, namely reversibility. If you apply enough heat and moisture to an MDF/veneer glue-up to reverse the glue, you also tend to turn the MDF back into the ooze from which it emerged. You end up with a gooey mess that is just about a throw away.
....... don't ask me how I know this.
I'm guessing that it was the glue holding the dust together that failed in your case, not the HHG.
Guess i need to get myself some higher quality materials..
The choise around here (unless from specialized and expensive dealers) is crappy plywood, extremely expensive birch ply and then MDF. No easy fix.
We all learn of our mistakes and sharing them is as important that sharing sucesses. Glad you did, Paul!
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