FRporscheman

Thanks for reading. I don't know what the best course of action is here. I don't think my little harbor freight welder is going to do a good enough job on this thin metal, trying to make a water-tight weld in a tight space without burning through the existing tray. I never liked fiberglass resin - I always see it separate and peel off after a little while. The only idea I thought of that I didn't shoot down was to just coat it liberally with permatex gray silicone. I suppose the evolved version of this idea would be to find some brushable seam sealant and apply that all over. How long would that last? Will it work to close and seal these holes and stop rust?

I'm open to any other ideas and any input in general!

m73m95

It looks like you took a pic of my car.... I have holes in the exact same spot.

I was going to just bondo the holes closed, then give it all a good coat of truck liner, or rubberized undercoating.

odurandina

high H20 area. grind and replace with a quality, epoxy resin such as Greg Loehr's Resin Research.

(he's also an acquantance of mine from the surfing industry). i would avoid using bondo there. epoxy is more stable.

m73m95

That would be why I'm using the truck liner.

Any super water that can get through that ****, can have it.

Grandpa#3

You still have to remove the rust with a wire brush wheel in your drill. Coat the area with a rust preventative paint, fill with epoxy and f.glass, and use bed liner to coat the whole area. Allow to dry and put on another coat of bed liner. Make sure the drain hole is kept cleaned out in the future.

Cheers,
Larry

J Berk

If it's done right you should have no issue with resin/fiberglass.

If it's still around, there is also a product called Duro-Easyglass...which is a bondo-like resin material with chopped up glass-fibers in it. I repaired my first car (a volvo) with that stuff 25 years ago and it still runs around westchester, NY with no signs of rust.

Just checked and I think this is the same stuff:

http://solutions.3m.com/wps/portal/3...glPZ748S0JMVbl

moorepower

I used this stuff to fill some small holes in my battery tray about three years ago: http://www.por15.com/PORPATCH/productinfo/PPB/
I wire brushed all the rust off and smeared this stuff into the holes. After it dried, I coated the whole tray with regular POR-15, and then with rubberized undercoat.

FRporscheman

I think when I repaired the tray in my 968, I used epoxy (there was only 1 tiny little hole), and I cleaned the whole tray and sprayed black rubberized undercoating. I was actually looking for truck bed liner but found the undercoating. That car's tray still looks good...

But this car is on a whole other level of F'ed. I need to apply so much of whatever I use I'm worried a pothole or hard corner might cause body flex which would crack the epoxy or resin.

I don't know much about bondo. Obviously it sticks to steel real well. But would the rust have to be 100% cleaned away, or is 99% good enough? I.e. will that tiny trace of rust spread like cancer and F me up later? How hard is bondo? I want a degree of flexibility.

That 3m stuff looks nice but they sell only a 6-pack for $82!

So far I think I'll go with the Por15, especially because of how it works on rust... It's not cheap though is it? Anyone know where to get brushable seam sealant though and if it's a good thing to use?

I was using a 3" wire wheel on my die grinder to clean the rust. I'd also use rust neutralizing gel, but I don't want it pouring through the holes and causing issues with whatever is under there! Should I prime the metal before applying epoxy, or bondo, or resin?

J Berk

Arash

Pretty sure you can buy the 3M stuff at an autobody store by the can.

Joe

m73m95

You would defiantly have to use a rust desolver. The area in my car isn't real rusty, just a few small holes. I'm going to tape off and cover everything very well, and soda blast the area.

The area isn't really a structural area, so I doubt bondo would crack. There is enough material around the small holes to dissipate what stress there might be. The bondo is just there to keep the bed liner from falling through the holes. If it did crack out during a track day or something, so what? The bed liner is flexible, chemical (battery acid) proof, and looks good. Your battery isn't in danger of falling on your passengers feet with the holes there, is it? The strength is there, just fill the holes.

I suppose you could also use some JB weld. That **** is indestructible.

Its weird, usually I'm the one posting in threads who is accused of "overkill"... This time, my fix isn't up to the scrutiny of RL

AScholtes

Look for a product called "RustBullit" It is made for this situation and will more than likly fill in the pinholes. Then truck bed liner over the area.

Bill

If this is a car you plan to keep, I would suggest you take it to a body shop and have them weld in a new panel. Your panel has rusted most likely because battery acid removed the paint, and is corroding the metal. I would not want to cover over acid with any material.

m73m95

Yet another reason to soda blast ..... its baking soda, which will solve the acid problem.

Mini-sand blaster

1. fill with baking soda
2. mask off and cover everything within a 3 mile radius (including inside the car, cause that's where the holes go)
3. blast the infected area
4. fill holes with your choice of material
5. paint on rino-liner.
6. have a beer, or 7

Another good thing about the baking soda is, its the same thing that automotive fire extinguishers are filled with, so if some does happen to get in and around sensitive parts, it won't hurt anything.

FRporscheman

Yeah, definitely keeping this car, it's been in the family since 1984. It deserves a weld job better than I can afford.

I'll go around to various auto stores and see what kind of resins and epoxies they have, and I'll look for rustbullet... but part of me is thinking I should use the next 9-10 days of sun as an omen that I should order the por15......

I'll try to cover the area under the battery tray to mitigate the splash damage from cleaners and water.

I pulled the carpet so I can thoroughly rinse and clean it (or replace). Is it sad that the paint under the carpet & insulation is in better shape than the paint on the outside of the car? LOL.

AScholtes

I wholehardedly cannot recommend por15... trust me, rustbullit it a million times better than por15 ever could be..