View Full Version : Pore filling with HHG

12-03-2011, 03:47 PM
Today's episode of the Woodwright Shop on PBS covered veneering using HHG (hot hide glue) so I paid attention.

I've never used HHG but have been following with interest all the conversations in this forum regarding its use. I don't know that I build enough to make using it worthwhile but I'm always interested in learning more about building.

In this episode they were veneering drawer fronts and then banding the outside edges. They applied HHG to BOTH sides of the veneer and after squeegeeing it in position and letting it set a bit they used a cabinet scraper to remove the excess glue leaving some to fill the pores.

I've never heard of this, anyone out there used this method?
Any advantages or disadvantages that you've experienced?
They mentioned that this worked well even if staining or varnishing.

12-03-2011, 07:50 PM
What part are you referring to. The veneering, or pore filling? Both are really old....and I mean many, many centuries old technique.

To veneer with HHG wetting out both the front and back of the veneer is necessary, as the water in the glue will swell the veneer unevenly if just on one side, causing it to curl up around the edges etc. It also acts as a lubricant when you are hammer veneering or rolling it on. I've used this method quit often.

For pore filling in fine grained wood it works alright, and as the glue dries very hard, it is easy to scrape smooth. However if it's not fine grained wood then your results will be less than satisfying if you think you are going to get away with one application. Also as HHG can pick up and loose moisture from the ambient conditions you could see those filled pores swelling and sinking depending on the conditions unless it's sealed quite well.

If you start to work up a sweat when scrapping the glue will get sticky if you man-handle the instrument. Just like liking a stamp, it reactivates the glue. Once it's all the way down to the pores this isn't an issue.

The real beauty of HHG is that it's invisible under finish...That is to say, unlike PVA's you will not see a great smear where you were less than diligent in your glue clean up.

Michael N.
12-04-2011, 02:16 AM
I've tried it. It works but you'll be there forever on open pored woods. HHG shrinks a lot!

12-04-2011, 09:00 AM
Thanks for the replies. I was mostly curious about the use of HHG as a pore filler.
Sounds like while it does work that maybe the epoxies are a better choice, in most cases.
Always nice to have options and understand how these all work and interact.

12-04-2011, 03:20 PM
I know that some mandolin builders do it on spruce tops because of the amount of end grain that is exposed from carving the arch in to the top. The idea is to seal it so that it takes stain the same as the rest of the top. I've always wondered if that was the origination of a burst finish. I've also heard of adding fine saw/sanding dust to it to make a slurry to reduce the shrinking.