[TheForge] Re: stubborn rivets

[Mike Spencer]

> my 2nd least desired solution is to use a welding tip on the torch
> and heat the surround metal to allow the rivet body to fall out.
>
> Option #2 would have been my first choice .

Not sure that would work as you think.  If you heat a ring, it gets
bigger in diameter beause the ring material gets longer linearly.

But if you heat a small region of the truck frame around the rivet
hole, it's surrounded and constrained by cold metal so I think the
hole would get smaller, thus tighter.  That could be good because
after cooling, the hole might be a tiny bit enlarged from crushing.
But it will be hard to heat uniformly all around the rivet, expecially
if, as I imagine, the mating flange of the bracket is hard up against
the frame.

I haven't used oxy-propane but if you have a welding tip that can
quickly heat the rivet itself to red heat, the rivet will try to
expand but will be restrained by the surrounding cold(er) hole. As the
rivet gets to (even dull) red heat, the force or the constraining hole
will crush the rivet a tiny amount, making it smaller.  It will also
crush any oxide between the rivet and the hole and, as rust isn't
malleable at a dull red heat, it wil tend to crumble and loosen.

> suggestions welcomed.

That, FWIW, is mine.  Good luck.


- Mike

-- 
Michael Spencer                  Nova Scotia, Canada       .~. 
                                                           /V\ 
mspencer at tallships.ca                                     /( )\
http://home.tallships.ca/mspencer/                        ^^-^^