Gluing small table tops with hide glue–what finish should be used?
I am converting to using hide glue for assembling small end tables and coffee tables.
I had been using PVA up to this point in all joints.
When finishing, I had usually used Seal Coat shellac, followed by multiple layers of water based polyurethane–these furniture pieces are being donated to needy families here in Portland ME. So a robust finish on the table tops is desired.
This method also allows me to apply finish in the winter in my basement wood shop, avoiding the toxicity inherent in many other finishes. Also, if I wish to stain the piece, then I incorporate Transtint into the shellac.
Question: Can I use hide glue for the table tops as well as the bases?
Hide glue is obviously sensitive to water and heat.
Thinking that a shellac seal coat followed by the polyurethane shouldn’t effect the hide glue as the former should protect the glue from any water.
Thoughts??
Replies
I'd think any finish would be fine. Yes hide glue is sensitive to water but a water based finish doesn't have that much water and will be drying out anyway. Worst case to a quick test piece with some scraps.
thank you!
Will do.
You have a good plan. Go for it. I recently did some restoration work on an early 1900's oak secretary gluing it back together with hide glue. It was then finished, as you propose, with shellac SealCoat and water based poly. No problems.
Good, then I will "go for it"!
I have never used hide glue but would comment that most antique tables were constructed with hide glue. It has truly stood the test of time, and trying to undo it with water is not an easy task.
I would expect (but cannot say from experience) that the shellac would add an additional layer of protection to the glue. It might also be prudent to wait a couple of days for complete drying before finish - wet protein is far easier to remove than thoroughly dried - compare the ease of removing egg from a utensil when it is a bit dried on after cooking compared with if it's been left overnight. The dry protein chains shrink and form a very close structure which resists water penetration - you have to wet the surface layers then they have to wet the next layer, and poly does not have that much water in it.
Thank you!
Hide glue is great. Have you ever had some squeeze out with yellow glue, wiped it off, and when you applied finish tyou could still see where the squeeze out was? That doesn't happen with hide glue. It's invisible under finish.
Water based finish won't weaken hide glue. You'd have to leave it in the rain for a couple days for that to happen.
My most common finish is 2 coats of Sealcoat and 2 or 3 coats of General Finishes water based poly. All coats are very light.
thank you John. BTW do you ever add 46-0-0 urea to the glue mix in order to extend "open time". It is said this works, but no one says to what extent this works. Will be using 192.
Do you have experience on this point?
Unless veneering, I always use liquid hide glue. Old Brown Glue. I get plenty of open time. I usually only use hot hide for rub joints and veneer.
When I use protein flies I mix them from chips and heat them on the bed of a 3d printer. This ensures it never goes above the denature temperature (like even double boilers do). I then put it in the fridge to store it. Keeps for weeks.
For hide glue I use your chips and I warm them on my 3D printer bed (though a double boiler is the traditional method, which works okish).
You really want to use the chips+water, not the bottled stuff as the bottle doesn't have all the advantages of chips (like that it tightens as it dries and doesn't need clamping, and you can control the viscosity and tack, etc).
Everything you describe should be fine. The only time I reach for PVA is when a dark glue line might scream at me in the end.
Super!
I use hide glue and often water based urethane and have had some minor problems with the glue lines raising just a bit after applying the urethane. this is after sealing the piece with a 1# cut of shellac after gluing up and before urethaning. it doesn't always happen. I am going to start doing 2 coats of the 1# cut before urethaning for critical surfaces like table tops and tops of boxes to see if that helps. I love using hide glue so I am going to get this figured out!
Still learning about finishes. What are the benefits of sealcoat followed by water based poly? Seems to a popular option for a number of experienced forum members.
the shellac sealcoat in this case is to be a barrier between the water in the water-based urethane and the water soluble hide glue so the water doesn't mess up the edges of the hide glue joints. it won't ruin the joint, but I was getting a tiny little ridge at the edge of the hide glue joint, probably from reacting with the water in the poly and slighting expanding. As I had just put the finish coat polyurethane on, planing the little ridge off wasn't an option. I'm hoping that 2 coats of the shellac sealer will be enough to prevent this. if you are planning on staining the piece with penetrating stain, you might not want to seal it so much as you will change how the piece takes the stain - you'd want to do a test piece first to see what happens. Does that make sense? I usually do a 1 pound shellac sealer before urethane anyway to even out how the wood accepts the urethane. one could always just use oil based urethane and then none of the above will be a problem, I just like working with the water based version with its easy cleanup, no fumes etc.
Thanks that makes sense.
Good thought! Hide glue is an excellent choice and compared to contemporary adhesives, it has a substantially longer shelf life. You may use any finish as hide glue is not going to interfere with any finish. Shellac seal coat is an ideal choice. Go for it.
This is not in any way responsive to your question, but congratulations for your work to help needy families. It’s a great way to make a positive difference, and it’s admirable that you would take time to do this.