Most people use wood jig blocks, I have done this a few times but never liked it. I played around in my shop and decided to try aluminum. It worked really well and allows enough offset off the table that tack welding doesn't char up the table.
I ran a test on a scrap piece of wood and it checked out fine. Really happy with this. Anyhow, if you're new to this and want to try something different you may want to try this. I just finished a photo intense blog post on my builders blog if you want the full story. http://cassuttairplane.com/index.php/2017/01/18/fuselage-jig-blocks/
Scrapper
I ran a test on a scrap piece of wood and it checked out fine. Really happy with this. Anyhow, if you're new to this and want to try something different you may want to try this. I just finished a photo intense blog post on my builders blog if you want the full story. http://cassuttairplane.com/index.php/2017/01/18/fuselage-jig-blocks/
Scrapper