Hey im starting my resto on my 120y and its got pretty minimal rust. ( lucky me )
but im considering what to repair it with.
I started fixing the quarter panels with stainless so it wouldn't rust but I now realise paint/bog may not stick to it very well.
im also considering fixing the small rust holes with fibreglass but am unsure if its a good idea or should I just use steel.
I tried googling a answer but it just confused me more.
can anyone shed some light on what material I should stick too or advice on what they did / tried and failed or sucseeded with

Just steel is your best bet.stainless no good at all

Fibreglass doesn't fix rust. But it can cover over holes acceptably.

Rust needs either to be cut out, or to be chemically stabilized.

After fixing the rust you can cover small holes with body filler or larger holes with fibreglass cloth. BUT if you don't seal it properly it will just rust again. So a proper coat of paint is important. Primer followed by paint on both sides.

Replacing holes with steel patches is the best way of doing it. But make sure you prime and paint both sides to prevent new rust from eventually forming.

I realise the rust would need to be cut out first to stop it coming back. im meaning if after I cut out the rust would replacing the whole with fiberglass be better than steel as it will stop the rust happening again.
the problem I see with steel is you cant always rust prevent / paint the inside if the fixed panel.
I don't know much about bog either but the little experience I have had its cracked within a couple of years. is that from a bad job or is bog just really fragile, this is also why ive been thinking about fibreglass as its pretty strong.

Quote:
No, it would not be better than steel. If you use a fiberglass patch, the steel can rust where it meets the fiberglass patch -- if moisture gets in. So whether you use fiberglass or steel patch, the coating is most important.

Body filler (bog) is only to be used in light amounts, and it won't crack. Thick coats will crack. So for tiny holes, filler is perfectly fine. For larger holes don't use filler or it will crack. Filler has no structural strength. For expert work, professional bodymen use filler only for touchup. For cheap work they might use it in thicker amounts, but then it won't last.

if you have to use bog try use metal reinforced bog some have metal and fiberglass mixed in it

seems to work well for filling small holes etc

but not really a substitute for new metal

Thanks!

get fiberglass out of your head...!
the only way to fix a rust patch is with steel... try to use the same thinkness steel..
For the panels that are inclosed, it is best to cut the rust out, sand the area of the cuts so clean metal is showing, then sand the new piece of metal. Then Zinc prime the inside of the inclosed panel and the side that will be inclosed of the new steel...
zinc primer is a primer that may slow and maybe prevent rust reacquiring in that area, and is also weldable..!!!
also try to wear latex gloves or something, because the oils from your hands Will start the rust on a new piece of steel

Awsome help thanks guys ill keep welding new steel in then.