Rikyrik81":2pu4c3ht said:
… Its not uncommon for glue joints to fail at work along the grain like a door panel, newel post, jamb etc im not talking about rail to style joints. I assumed the joints fail due to shrinkage of the timber used. It is supposed to be low on moisture content but I suspect its not as low as it should.
Firstly, both Everbuild brand D4 resin or their 526 resin, for example, are as good as any other brand of similar wood adhesive formulations. Everbuild supply a wide range of adhesives for various applications; I've used a decent range of their products and found them to be reliable, if used correctly.
Therefore, I think you can generally discount this adhesive brand as an issue with regards to joint failure at both your employer's business, and in your walnut table project, but, as is the case with all wood adhesives (except one) they only work with dry wood. By definition, dry means wood at, or below, 20% MC. So, yes, if your employer is using wood wetter than this to make joinery products such as doors, newel posts, windows, stairs, panelling, etc, which is highly unlikely I'd suggest, you can expect glue joint failure on a regular basis. If you are experiencing regular glue joint failures as you describe at your work, I strongly suggest you (or your company's quality controller) look at your work methods, and the quality of your wood prior to building your products.
On a side note, the only wood adhesives that work with wood wetter than 20% MC are the polyurethane adhesives, available from a range of manufacturers, including Everbuild.
Rikyrik81":2pu4c3ht said:
The way i glue up along the grain joints is to get the edges straight on a plainer ofc and in most cases biscuit joint, i like to glue both joining edges and allow for dry patches to occur then reapply and clamp up for at least12 hours. Ive never known a better method in 20plus years but open to suggestions.
Your edge preparation methodology seems to a bit hit and miss. How carefully do you check for a correctly formed edge after the boards come off the surface planer? Are there gaps at either end that have to be closed tightly, for example? If there are gaps at either end prior to the glue up, that's not good. Your adhesive application following your joint preparation is ... well, er, eccentric. You don't seem to follow the adhesive manufacturer's adhesive application guidelines for some reason. What's the strange double application of glue thing going on for? There's no need for it if the joint(s) is/are prepared properly in wood that's smooth and dry.
Finally, I'm rather wary, like Trevanion above, of being accused of trying to teach a fellow working woodworker how to suck eggs, but you might find some useful guidelines about edge joinery
at this link to an article at my website. Slainte.