First time edge glueing boards

[Philw]

Hi chaps, I have yet more questions on my walnut table. I have finally purchased some clamps (bessey parrallel 4 for £100) and table legs so am now very much ready to glue and get going!

Question numero 1, and the big one. One of my boards remains bowed by 4mm in the centre (see photo 1) can I clamp and glue this out or will it cause big problems later on?
Question 2, what grit should I sand to on the board edges?
Question 3, does anyone know where to get an appropriate steel c section powder coated black from to reinforce and reduce movement ? My stock is 42mm thick so assuming no more than 50x20mm

 

[Jones]

Don't sand surfaces to be glued . It just fills the pores with dust that won't brush, hoover or wipe out and that stops the glue contacting the surface effectively and reduces joint strength. Also do your glue up before workshop dust has settled onto fresh surfaces. If your planks are 42 mm thick you won't be able to straighten them with glue and biscuits so plane them flat before glue up.

 

[TheTiddles]

That 4mm is a lot, unless you are working in narrow pieces I’d get them flat first.

Are you after pre-coated steel? If so when you cut it, there will be an un-coated edge which is a bit naff. Better off making the steel section you need and having it coated, it’s not costly, but round the edges and corners well

 

[Blackswanwood]

You may have already seen it but if not there is an excellent post here which may help …

https://www.ukworkshop.co.uk/threads/how-to-edge-joint.112936/

 

[John on the Wirral]

Hi, When producing wide pieces of timber eg.tops we would often rip up the timber into narrow pieces and then glue them back together alternating the heart ie wood warps(cups) away from the heart. When gluing the strips back together we were taught to only use rub joints and avoid clamps. a long trying plane was used so that the edges were perfect before gluing. The glued joint was rubbed backwards and forward along it's length until it became very stiff and was finally tapped into place and left to dry -the perfect edge joint but if you tapped it sideways the joint would fall apart but once dried it was solid. Because the effect of cupping had been minimised planing to flat was possible without sacrificing the thickness.