# TBIII or T88 for a M&T joint



## harum (Nov 25, 2013)

While working on M&T joinery for a bench, I realized that in some butt joints the walls of mortises are endgrain and tenon cheeks are long grain, like in a stretcher-to-leg joint. Even if my M&Ts have a decent tight fit, would it be safer to use an epoxy adhesive, like System Three T-88, instead of Titebond III to strengthen the endgrain to long grain bond for a long term use-and-abuse? Or is this where several dowels will be stronger that a M&T?

The manufacturer of T-88 says that:
"The adhesive may be used without modifications in normally fitted joints, and will cure in any thickness without shrinkage. T-88 is clear amber and becomes virtually invisible when varnished."

Doesn't it mean that it would be superior to TBIII in terms of *long term * stability/strength for any grain directions in gluing surfaces?

Would appreciate any comment!
Best wishes, h.


----------



## TheFridge (May 1, 2014)

I wouldn't worry too much.


----------



## harum (Nov 25, 2013)

Well, this is my first project where joinery strengh will be actually tested daily and will have to support hundreds of pounds of weight. Besides, I should have said that while my M&Ts are tight, the tenon cheeks and mortise walls are not anywhere near hand-plane smooth; some patches feel pretty rough. Therefore, the actual gluing surface might be smaller.


----------



## bondogaposis (Dec 18, 2011)

Epoxy has gap filling properties, where as TBIII does not. So from the information you have given I'd go with the epoxy. However not knowing how or what you are building there might be a better way to construct your joinery. It is always better to rely on the joinery rather than glue for strength.


----------



## wormil (Nov 19, 2011)

I would use tb3 and pin the tenons. I pin all mine.


----------



## harum (Nov 25, 2013)

> However not knowing how or what you are building there might be a better way to construct your joinery. It is always better to rely on the joinery rather than glue for strength.
> 
> - bondogaposis


This is just an entryway bench with splayed legs, 18" high, wide enough for two people. Yes, the joinery so far is pretty tight, even without glue. However, not sure how cross-grain and engrain to long grain gluing is going to hold long term with racking, sagging, etc.


----------



## 1brian (Aug 20, 2018)

This is on my kitchen table, walnut leg and spreader, oak wedge. Tight as can be with just friction.










Of course it was the first one I did and my dimensions are to say the least, loose.


----------

