On Wed, 19 Sep 2007 17:23:13 +0000 (UTC), Fortunat1 wrote:


While we're on the subject, I have a question about Rosette welds. With the
specified hole size in realtion to the thickness of the metal, I have a
hard time getting the metal underneath to heat up enough to melt before I
blow away the metal on top. I have preheated the innner piece as much as
possible and this does produce better results, but It's still a bit hit and
miss. Is there a trick? Smaller tip? Bigger?

This is first cousin to the posting I just made concerning welding an
inner sleeve. Unfortunately, the solution is probably different.

What I was shown was to drill an 1/8" hole in the top layer, aim the
flame at the inner piece and let the 1/8" hole melt back. by the time
the hole increases to 1/4", the inner piece will have formed a
puddle. Give her a try on some scrap; I tried it with two pieces of
sheetmetal and it worked. - Mike