Bessey Warranty

[Mortiser]

Regarding flat panels and glue-up...  you might check this out:

Be careful about over-tightening. I had that problem when I started years ago.

 

[Tom the Remodeler]

There are equivalent router bits for that joint (Infinity Tools has one here:https://www.infinitytools.com/glue-joint-router-bits ), but does using that bit prevent bowing/cupping when clamping? Sure, using those bits or biscuits or dominos can help with alignment at the edges, but that's not the whole story. And those profiles aren't suitable if the end grain is visible, at least for my aesthetics.

I mostly deal with 6/4, 8/4 and 12/4 material, so as long as the blanks are S4S'd properly there's usually little- to no- risk of bowing/cupping when performing the glue-up. I've found that using the Bessey I-Beam clamps helps as well since the bar is less susceptible to flexing, as compared to the K-Body clamps where I've found the longer bar to flex under heavy loads, risking transferring the bow to the assembly.

Regarding the glue joint cutter, I'm not certain if it helps prevent bowing or not, but, properly dialed-in, it results in a seam that really doesn't require any work beyond finish sanding, and I usually try to hide end-grain so the joint is a non-issue, that I could see someone taking offense if the end-grain is a visual element.

 

[Tom the Remodeler]

A shaper/spindle moulder is beyond the average home workshop, but for making exterior doors, it really is the best way to do all of the joinery.

Agreed, it's overkill for most hobbyists but I figure there are a handful of professionals still lurking here so it was worth mentioning.

I recently acquired the Adjustable Finger Joint Cutter, it makes quick work of end-grain joinery on arch- and elliptical- top doors/windows.https://rangate.com/products/adjustable-finger-joint-cutter

 

[smorgasbord]

Regarding flat panels and glue-up...  you might check this out:

Yes, that was the "clamp bars above and below the stock" technique I referred to, with the added technique of loosening clamps that are pulling the stock out of flat.

Does anyone actually do that? What are the results in terms of glue line appearance? It strikes me that once you've tightened a clamp, loosening it enough that the boards actually move (the whole point) means that you're creating a joint gap and the glue may not flow back into that gap since you've squeezed some out, impacting strength.

In Bent's case it appears that the clamp bars are the culprit in terms of bowing, since he always loosens a clamp to bring the boards back into flat. I'm assuming - and I could be wrong - that his edges are properly jointed and so it's not just high clamp pressure that's making them bow, but that high clamp pressure is making the Bessey bars bend, and that bending force pushes the stock up, causing a bow.

This is where cauls can be useful, but perhaps if you've got enough clamps, one could stack them in pairs - one above and one below right next to each other. Then the bows caused by bar bending are offset as you tighten them together.

 

[petar73]

Just for the record, I wrote to besesey.de about the broken jars and they sent me new replacement jars from Germany free of charge. They were very prompt and all they asked was to send them some pictures.