Rant: Just found out my bookcloth glue is slowly eating my covers

I was rebacking an old encyclopedia last week and noticed the covers were getting soft and crumbly. Dug into it and found out my PVA glue has a pH of like 4.2 or something crazy low. I got this glue from a supplier in Portland 3 years ago and never thought to check. Anyone else ever tested their adhesive pH or am I just paranoid?

2 comments

2 Comments

paul2331mo ago

Guess I should test my glue before my books dissolve into dust.

fiona3321mo ago

Oh man, @paul233 you might want to borrow my pH meter if you're thinking about testing. But honestly, I have to push back a little here. That low pH might be doing you a favor if those old encyclopedias have acidic paper anyway. High-acid PVA can actually help slow down the degradation of already acidic materials by counteracting the alkaline environment some people try to create. Plus, if your glue has held for three years without total disaster, maybe it's built a stable bond that's tough to break. Just a thought before you toss it all out.