I posted a forum topic recently asking about the best way to attach some veneer to a project I am planning and one of the recommendations was to use hot hide glue (HHG). I’ve seen posts before from fellow LJs about how much they like using HHG and have been meaning to to give it a try so I decided this was a good excuse. I will share my journey in this blog.
Step 1: Research.
I spent a couple of days understanding the history, uses, pros and cons, tools and techniques. Of course fellow Lumberjock and resident HHG evangalist Shiprwright’s blog series Hide Glue for Beginners is a great place to start for anyone interested in trying HHG. Shipwright also has several posts, projects and reviews related to HHG including improvising the tools on the cheap and the tips he provided in my forum post about veneer mentioned above helped convince me that this was the time to at least give HHG a try.
Step 2: Get the tools and materials.
A: The glue pot. You are going to need a way to “cook” and maintain the temperature of the glue once you mix up a batch. You need a heat source and a pot, preferably one that works like a double boiler where the container that holds the glue actually sits in water that is heated. The modern pots are expensive so cheaper alternatives for just trying it out are a small slow cooker, a coffee pot or an antique glue pot on a burner. Lee Valley also has a small antique style pot and warmer that is pretty reasonably priced. I found an antique glue pot for about $25 on eBay and it looked so cool that I decided I wanted it regardless of whether I use it.
Note that the pot is welded to an antique electric warmer that was built before UL listing and was too dangerous to use. Not sure how they used this thing without electrocuting themselves. I will have to grind off the welds to use this pot.
For my first few attempts, while I am cleaning the rust out of the the antique one (the outside discoloration is old glue), I am using a small slow cooker for the hot water bath and an empty plastic spice bottle to mix and heat the glue in. I also ordered a hot plate from Amazon for $10 that I hope will work with my antique pot once I have it cleaned up. Because the glue needs to be maintained between 140 and 160 degrees I also ordered a meat thermometer to keep an eye on the temperature.
B: Glue brush. I have some cheap disposable acid brushes that I will use for the first test (below) but I also found a brush intended for gluing book bindings that I hope will work well when I finally get to the veneer project.
C: The Glue. My local Woodcraft was having a 10% off almost everything in the store sale so I picked up some BT&G 192 gram flakes.
D: Veneer Hammer. The Kunz hammer is about $60 retail but I bid on and won a practically new one on eBay for $30 including shipping. There are plenty of shop built examples and workarounds on LJ that were my backup plan.
Step3: Mix Up a Batch of Glue
I primed a small slow cooker with some boiling water and plugged it in. I didn’t want to waste a bunch of glue so I put about 3 heaping teaspoons of flakes into an old spice bottle and covered the flakes with tap water. I let it sit for a while to absorb the water, used a stick to make sure that the flakes at the bottom were saturated, sealed the bottle and put into the hot water. The slow cooker was having trouble maintaining the minimum 140 temperature so I added some more boiling water to bring the temperature up to about 150 and let it cook for almost an hour before it reached what I thought was the right consistency. I think that I got lucky because once it finally got hot enough, the consistency was like a fairly thick maple syrup.
Step4: Ready to Slap it on Some Wood
I had a couple of small scraps of plywood laying around for my first try. Since I ultimately want to try this with veneer I also found some thin scraps, though they are thicker than typical veneer and pretty small. I put a dab on one end of the plywood and pinched the 2 pieces together by hand for about 2 minutes for a basic 90 degree lap joint. It moved around a little and I didn’t really try to make it square or anything so I can see that I will have to be careful that the pieces don’t move around while waiting for the glue to set. I set it down when the squeeze out (I used way too much glue I think) started to gel. After about 5 minutes I smeared glue on one whole side of one PW scraps and presses 2 small thin strips to the surface, again by hand, until I got no more squeeze out. It was very easy to move them around to line them up. After finishing up, I let the spice bottle of glue cool off and put it in the mini fridge I have in the shop (right next to the IPA).
Step 5: Test the joint.
About 2 hours later, I decide to see how good the joints were. I couldn’t break it by hand so I clamped it into a vice and whacked the heck out of it with a hammer. It didn’t budge. After just 2 hours, this joint seems to be every bit as strong as a PVA joint that has cured for 24 hours. Very impressive.
Step 6: Clean Some of the Squeeze Out
I didn’t bother to clean off any of the glue before it set so I had some pretty big globs of glue on the scraps. I used a warm, wet paper towel to remove some of the excess glue just to see how easy that is. I was able to get all of the glue off the surface of the 2 strips. The areas where I left some significant squeeze out and where I left a thick coat on the surface were not as easy but I could have eventually removed it all by spending a little more time. I tried using a chisel to cut some of the thicker squeeze out off but the glue was pretty hard and that didn’t work as well as I thought it would. Next time I will at least wipe the squeeze out off before it completely sets so that the remaining glue is a just a thin film and that should make it easy to wipe off with a warm wet cloth.
I can see why so many people love HHG. For small or quick glue up, it will be much easier to just reach for a bottle of PVA rather than mixing and heating up a batch of glue but for a large glue up with complex or tight fitting joinery, I can see that this could make those easier. Since my garage shop gets cold in the winter, even though I have a couple of heaters out there, it may require some extra steps to make sure that the wood is warm enough that the glue doesn’t set before the parts are in place. But that will be a future experiment. I am sold that this will become a useful option going forward.
-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.