I think I have made a mistake with my Telemaster 40 wing joint. I used 1.5 oz cloth on the wing center section. I am wondering should I just double it another layer or add maybe put a heavier cloth over the 1.5 oz.?

the joint without the glass is strong enough if done properly. the 1.5 oz cloth just adds to the strength of the joint... you really don't have to add the epoxy and cloth so if it were me i'd leave it, however if it makes ya feel better double it up. BTW I also glass my wing joints... on a .40 size 2oz cloth is what i use more than enough IMHO.

John

Ive seen plenty of people with just the glassed section left after a dunb thumb !!!!!!

Leave the glass as it is. Any more is just additional weight and a larger bulge under the covering.