On Fri, 22 Apr 2011 19:51:24 -0700, "Califbill"
wrote:

I am doing some rebuild on my aluminum river jet boat. Going to weld closed
some old bolt holes in the gunnel and dash. What is a good backing plate to
prevent a big gob of aluminum slump on the backside, where I can not get the
grinder after I use the spool gun on the top. If I had a TIG outfit, might
be easier, but only a spool gun. 1/4" steel plate? Stainless plate?
Copper plate.