There are many types of wood glue, and it can be confusing which one to use. Specialty glues are more expensive, but are they better? Let’s take a look at hide glue vs PVA wood glue and when each one is appropriate.
Advantages of PVA wood glue
PVA wood glue has several advantages. You can buy it pretty much anywhere, it’s pretty inexpensive, and it’s really strong. You can get specialty formulas for special applications, but generally speaking, even the common generic looking wood glue gives a bond that’s just as strong as the natural wood as long as you clamp it and let it dry completely before stressing it.
For permanent bonds, it’s hard to beat PVA wood glue. It’s inexpensive, works well, and has a long shelf life. I use it for household repairs and can’t remember a time I had a problem with it that wasn’t my own fault.
So why do people even talk about hide glue anymore?
Advantages of hide glue
Hide glue lacks many of the advantages of PVA glue. When it comes to hide glue vs PVA glue, there are two advantages in favor of hide glue. Hide glue is less permanent.
Why would you want glue that isn’t permanent?
Normally when you glue wood together you want it to stay together forever. But when you’re talking heirlooms or antiques, there are some circumstances when you need to be able to take them apart. Sometimes to properly repair a piece, you have to take it apart. You can remove hide glue with vinegar and heat and lots of patience. Removing PVA glue is much dicier.
A professional restorer will tell you to never use PVA glue on the joints of an antique or heirloom. PVA is fine for repairing splits or breaks that shouldn’t be there, but any pieces of wood that are separate components need to be glued with hide glue in case they ever need to be disassembled in the future.
Thinning hide glue
There is one more advantage to hide glue. When you warm up hide glue, it gets thinner. This can be useful in certain repairs. Let’s say you have a thin crack and it will be difficult or impossible to disassemble the piece to get enough PVA glue into the crack to repair it. You can heat up hide glue to make it thinner. Much thinner than PVA glue. This lets you put the hide glue into a syringe and inject it into the split. Then you can clamp up the piece. If you don’t get squeeze out, remove the clamp and inject more glue.
This can let you complete a tricky repair that you might not be able to do with PVA glue. You can inject PVA with a syringe, but it may not soak all the way down into where you need it to go. Using a thinner glue helps in this application. All other things being equal, PVA wood glue will be stronger, but this application isn’t a fair fight.
Then again this is also a very niche application. That’s why most people buy and use PVA wood glue most of the time.