Hammer Veneering

[Steve Friedman]

I am about to try hammer veneering with hot hide glue for the first time and have come across a slew of contradictory advice.  Looking for some help sorting it out.  It's a very small project - 8 pieces of veneer around 1" x 12" each, but they're getting attached to the S-shaped edge of some corner brackets.  There are 4 questions:

1.  Do you use the glue to size the surface?  If yes, the substrate, the veneer, or both?

2.  Do you apply the glue to the substrate, the veneer, or both?

3.  Do you apply the glue and then start attaching the glue right away or do you wait for it to dry and then use an iron to heat the veneer and melt the glue?

4.  Do you use let the melted hide glue sit overnight before using it or so you use it right away?

This is my 3rd time trying to veneer the edges of these brackets and I would like it to be the last.  My first 2 attempts were with heat-lock glue and an iron.


Wasn't sure about whether to post this here or 2 floors up, but figured hammer veneering with hide glue belonged here.

Thanks in advance.

Steve

[Harthag]

You might benefit from watching this episode of The Woodwright's Shop.  Seems to provide a nice broad-strokes introduction to the technique.

http://www.pbs.org/video/the-woodwrights...eve-latta/

[barryvabeach]

Steve,  Latta is an artist, and I am more of a hit and miss, but I can answer a few questions.

  I generally don't size the substrate or the veneer, though I don't see any reason why you couldn't size the substrate

  In general, hammer veneer uses hot hide glue.  You apply it to both surfaces of the veneer, and to the top surface of the substrate, then use the hammer to squeeze out the glue.   The glue on the top surface of the veneer just gets squeeged off by the hammer, but it allows the hammer to slide easily, and it reduces the tendency of the veneer to curl.  If you want to see curl, just spray one side of a piece of veneer with a little water and wait a minute or so, and the moist area will expand, and the dry side will curl so it looks like a U.   I have seen a suggestion that a mildly damp cloth be put on the top of the veneer after you have finished hammering it to keep it from drying out too quickly, which will cause the veneer to curl away from the substrate.  This is the same principle that required that you apply veneer to both sides of most pieces of work.

The hide glue is  applied while still liquid and warm ( around 140 F ) , as it cools it solidifies and sticks.  One way to sort of test it is to rub a dab between your fingers for a few seconds, if your fingers start to stick together as it starts to cool, the glue is working.   I usually keep the glue in the hot pot most of the time, take it out to get some to apply to the work, and return it to the pot so it stays warm.  When you are done for the day, put it in a container and through it in the fridge, it keeps there for quite a while .  

 I don't know the real theory, but I envision it like you have covered the entire surface with glue ,  and as you use the hammer to squeeze the glue out of the middle, a vacuum, and atmospheric pressure hold it in contact till it cools and becomes solid.  

There is another method to applying veneer without using hide glue or clamps, and I have done that a few times with pretty good results.  You coat the topside of the substrate with a diluted solution of glue and water ( can't recall the portions right now, but probably not critical, just want the glue to flow easily ) and apply the same mix to the bottom of the veneer, and let both dry completely.  Don't apply size to the top of the veneer, yes it will curl when wet, but should flatten back as it dries.  Once completely dry, you put the veneer in place, and use an iron on top of the veneer ( usually with some brown paper in between to protect the veneer ) and apply gentle heat until the glue size melts, then continue to apply pressure, but not heat, with a veneer hammer  until the veneer sticks.  The main benefit of this approach is that since you are not applying moisture to the bottom of the veneer, you don't get as much of a tendency of the veneer to curl. 

I suggest you practice with some small test pieces on a flat surface to get a feel for the process.  

Finally, some suggest that you tap it once it has cooled to see if there are any areas that are loose, and it so, you then you an iron to warm them and dissolve the glue in that area, then apply pressure as it cools.

[Hank Knight]

Barry pretty much nailed it. My only suggestion is to not be stingy with the glue. Slather it on both sides of the veneer and the top surface of the substrate. You'll waste a good bit as you squeegee it off with the hammer, but lots of glue helps prevent voids or dry spots. As you squeegee the glue off with the hammer, you'll feel the point where the glue tacks and holds the veneer in place. When this happens, you're almost done and things begin to progress pretty fast. Continue to use the hammer to force all the excess glue out from between the veneer and the substrate. If the hammer begins to drag on the veneer, apply more glue as lubricant. It will get squeegeed off but it will prevent the hammer from catching and tearing the veneer. When you've got it all nice and smooth and flat, set it aside to cool and dry. Then sand carefully to remove any dried glue from the surface. Don't worry, once it's dry, hide glue won't interfere with stain or finish.
Good luck. It's fun to do.

[Steve Friedman]

You might benefit from watching this episode of The Woodwright's Shop.  Seems to provide a nice broad-strokes introduction to the technique.

http://www.pbs.org/video/the-woodwrights...eve-latta/

Thanks.  I had seen that, but re-watched and it was very helpful.  It seems to be the same technique that I saw on Tom Fidgen's YouTube video.

Thanks

Steve

[hbmcc]

Steve you do the coolest stuff. Is this a summer house (vacation) project too?

[Steve Friedman]

Steve,  Latta is an artist, and I am more of a hit and miss, but I can answer a few questions.

  I generally don't size the substrate or the veneer, though I don't see any reason why you couldn't size the substrate

  In general, hammer veneer uses hot hide glue.  You apply it to both surfaces of the veneer, and to the top surface of the substrate, then use the hammer to squeeze out the glue.   The glue on the top surface of the veneer just gets squeeged off by the hammer, but it allows the hammer to slide easily, and it reduces the tendency of the veneer to curl.  If you want to see curl, just spray one side of a piece of veneer with a little water and wait a minute or so, and the moist area will expand, and the dry side will curl so it looks like a U.   I have seen a suggestion that a mildly damp cloth be put on the top of the veneer after you have finished hammering it to keep it from drying out too quickly, which will cause the veneer to curl away from the substrate.  This is the same principle that required that you apply veneer to both sides of most pieces of work.

The hide glue is  applied while still liquid and warm ( around 140 F ) , as it cools it solidifies and sticks.  One way to sort of test it is to rub a dab between your fingers for a few seconds, if your fingers start to stick together as it starts to cool, the glue is working.   I usually keep the glue in the hot pot most of the time, take it out to get some to apply to the work, and return it to the pot so it stays warm.  When you are done for the day, put it in a container and through it in the fridge, it keeps there for quite a while .  

 I don't know the real theory, but I envision it like you have covered the entire surface with glue ,  and as you use the hammer to squeeze the glue out of the middle, a vacuum, and atmospheric pressure hold it in contact till it cools and becomes solid.  

There is another method to applying veneer without using hide glue or clamps, and I have done that a few times with pretty good results.  You coat the topside of the substrate with a diluted solution of glue and water ( can't recall the portions right now, but probably not critical, just want the glue to flow easily ) and apply the same mix to the bottom of the veneer, and let both dry completely.  Don't apply size to the top of the veneer, yes it will curl when wet, but should flatten back as it dries.  Once completely dry, you put the veneer in place, and use an iron on top of the veneer ( usually with some brown paper in between to protect the veneer ) and apply gentle heat until the glue size melts, then continue to apply pressure, but not heat, with a veneer hammer  until the veneer sticks.  The main benefit of this approach is that since you are not applying moisture to the bottom of the veneer, you don't get as much of a tendency of the veneer to curl. 

I suggest you practice with some small test pieces on a flat surface to get a feel for the process.  

Finally, some suggest that you tap it once it has cooled to see if there are any areas that are loose, and it so, you then you an iron to warm them and dissolve the glue in that area, then apply pressure as it cools.

Barry,

Thank you so much.  That is incredibly helpful.  Your process seems like Latta's, which appears to be pretty straight forward.  The second technique you described is similar to what I saw demonstrated in a video by David Savage.  It was one of the things that prompted my questions.  I guess there's more than one way to skin a cat.

The practice suggestion is a great one and I had definitely planned to do that.  I was going to first practice on a flat piece and then on something similar to the curve that I'm attempting because I'm concerned about being able to apply enough hammer pressure on the convex parts of the S-curves.

I have also seen the tapping technique done, but appreciate the reminder because I had already forgotten about it.

Thanks again for taking the time to type all that.

 Steve

[Steve Friedman]

Barry pretty much nailed it. My only suggestion is to not be stingy with the glue. Slather it on both sides of the veneer and the top surface of the substrate. You'll waste a good bit as you squeegee it off with the hammer, but lots of glue helps prevent voids or dry spots. As you squeegee the glue off with the hammer, you'll feel the point where the glue tacks and holds the veneer in place. When this happens, you're almost done and things begin to progress pretty fast. Continue to use the hammer to force all the excess glue out from between the veneer and the substrate. If the hammer begins to drag on the veneer, apply more glue as lubricant. It will get squeegeed off but it will prevent the hammer from catching and tearing the veneer. When you've got it all nice and smooth and flat, set it aside to cool and dry. Then sand carefully to remove any dried glue from the surface. Don't worry, once it's dry, hide glue won't interfere with stain or finish.
Good luck. It's fun to do.

Thanks Hank.  It will be interesting to see if it works, but I'll find out soon enough.  Planning to soften the veneer tomorrow and (hopefully) do some veneering on Sunday.

Steve

[Steve Friedman]

Steve you do the coolest stuff. Is this a summer house (vacation) project too?

That's funny.  No, not a vacation project.  Vacation is just a faint memory by now and few of my "projects" are traditional.

These are corner brackets from the canopy that I build for my daughter's wedding 4 years ago.  A family member is getting married and asked to borrow it for the wedding.

It's just 4 posts (around 3" square) and 4 rails (around 2" x 3") along the top, held together with loose tenons.  But it's around 5' x 7' and 7' tall and was built to be able to be easily disassembled, with no hardware exposed.  So it wobbled.  The corner brackets solved it, but I used veneer on the edges of the brackets to hide the hardware that's keeping them attached.

Steve

[Phil S.]

A good article here by Don Williams on hammer veneering -
https://www.popularwoodworking.com/techn...eneering-2

I also have his video on parquetry which has a good demo of the process -
http://www.shopwoodworking.com/simple-pa...-bl-161111