epoxy &fiberglass vs bondo & stainless mesh for rusty fenders??

[bryanhawaii]

I just watched a couple of youtube instructionals on epoxy &fiberglass vs bondo & stainless mesh and both have their merits and are equally messy. I have these big rust holes on the fenders of my old Ford 1900. Without grinding the metal down, they are many as big as a nickle, but after grinding the rust away, they'll be even larger so lotsa fill material, bridging and nasty work either way I go.
So, I'm asking you guys what is the preferred method to fill holes and why do you say so. any tips and/or feedback appreciated.............
Thanks in advance and
Aloha!!

 

[radios1]

epoxy &fiberglass is much stronger, and won't crack and fall off like bondo will!.. lead or welding is best though. this can be done if the metal is not tempered, like on the new cars, it will warp if tried on them.. lead was used widely on the older cars.. auto body repair with lead - Google Search

 

[chim]

Cut back to good metal and weld patches in. Anything else is more of a cosmetic fix.

 

[Egon]

Brush & grind off as much rust as you can. Spray it with rust stabilizer. Form a metal patch for the inside and the outside. “Sandwich”
For fastening use a high quality construction adhesive and screws or rivets to cinch it all together. Use bondo for smoothing things out.

The construction adhesive gets troweled on, has good open time and will remain slightly flexible. If using screws to pull it together most could be removed when all is cured. You can also use a ball peen hammer to make dimples that the screw head sits in and can be covered with bondo.

Make sure all is covered with a rust inhibitor before joining.

 

[ruffdog]

Flex-tape!

 

[bryanhawaii]

It seems that there are a lot of ways to do the job. Cutting and welding is out of my league and pocketbook, so I'll probably go with fiberglass and resin that I am somewhat experienced in with surfboards and lots of patching things. One simple question is:
should I attack the undersides first, then do the top [outside]? Luckily it's easier to access the undersides on a tractor fender than a newer car. And on the undersides, I may want to do some 'undercoating' if I can find it in white.
Thanks guys for all the input.
Aloha,

ruffdog............what is flex tape and how strong is the finished product?

 

[ruffdog]

ruffdog............what is flex tape and how strong is the finished product?

Flex Tape is a rubber based tape with a strong adhesive backing that can be used to repair many things. There have been plenty of ads/videos about the product. It comes in white, gray, black, clear, and ????. You can get it in wider widths too...like this 8" wide x 5ft long:

https://www.homedepot.com/p/Flex-Tape-8-in-x-5-ft-White-Strong-Rubberized-Waterproof-Tape-4-Piece-TFSWHTR0805-CS/302642975?cm_mmc=Shopping%7CG%7CBase%7CD24%7CMulti%7CNA%7CPLA%7CAll_Paint_Smart%7c71700000048001153%7c58700004793621602%7c92700041080546203&gclid=Cj0KCQjwwIPrBRCJARIsAFlVT8-LcMKyA0eo4o8HtZrUJj8G8R0lw_M4iWGxKYEfc5qsVjMmsX2tFcIaAoOgEALw_wcB&gclsrc=aw.ds

 

[ray66v]

I have a lifetime of experience repairing fenders.

There are no merits to using fiberglass, or Bondo, (including Duraglass), to fix rust holes. Except to those who choose to fix everything with duct tape.

The only way to properly repair a rust hole is to weld, or braze a metal patch in with a solid, leak proof seal. Then, you can apply body filler to make the surface smooth, as necessary.

Yes, you can do some repairs to a relative degree of success, using automotive epoxies to attach metal patches, or repair parts. However, the repair edge can shrink up and become somewhat visible over time. This is often fine, on an older vehicle, or a tractor.

 

[bryanhawaii]

Thanks guys, you may have given me a simple plan for the repairs. How does this sound..........grind down the undersides, treat with phosphoric acid and primer, then apply flex tape to bridge the holes from underneath then [will flextape accept any kind of paint/coating?], then attack the top [outside] by grinding down to bare metal and treat with rust preventive, fiberglass over holes and flextape applied from under and finish with bondo. not for a showroom finish but structurally sound and retarding rust for a few years. ..............can do??
Thanks again and Aloha

 

[Egon]

Sounds good.