battery tray rust

Birdibus · Post by **Birdibus** » Sat May 03, 2008 10:40 am

I removed my dead battery from the '71 bus and have cleaned the compartment. It is very rusty in there and several holes have formed next to the battery.

I have two small cans of POR15 and some fiberglass fabric. I've been doing the prep for POR15 and am almost ready to begin painting. My question is, do you think it would be a good idea to embed some of the fiberglass fabric over the rust holes using the POR15 as if it was resin?

I was thinking of two or three layers of paint, then the fiberglass, then more paint... then maybe even a second layer of fabric and paint. I would leave a hole in each patch for water drainage.

Should I make a fabric/paint patch to the underside? Or only the inside of the engine compartment?

battery tray rust
[albumimg]2017[/albumimg]
battery tray underside
[albumimg]2018[/albumimg]

bretski · Post by **bretski** » Sat May 03, 2008 2:25 pm

POR15 and its ilk work great with fiberglass mesh. After prepping your surface, put down a thick coat of the paint. Lay down the mesh, then paint another coat over the top of the mesh as a "resin".

Do the same for the underside, and you'll have a nice solid repair after it dries. Once the POR15 is fully cured, put on a top coat of automotive paint in the compartment, and a layer of rubber undercoating (on the underside of the tray). Call it good.

I've done a similar repair on a much larger hole than yours. Worked great. I'll dig out some photos at some point and post 'em.

Westy78 · Post by **Westy78** » Sat May 03, 2008 2:50 pm

That's exactly how I "fixed" the passenger side tray on my bus. Once the POR/fiberglass dries it's extremely hard. I painted over it with paint that I had mixed up to match the Dakota Beige and it looks pretty good. I think I did two layers of the glass mat. Make sure that you still drill a hole for the tray to drain if you cover over it.

Birdibus · Post by **Birdibus** » Sat May 03, 2008 8:00 pm

Hee hee, good! I'm glad it's a good plan. I think I'll scrub it one more time with the degreaser, for good measure, and put on the metal prep tomorrow.

That is the only spot on my bus with serious rust. We have so little rain I'm sure the patch will be fine. I'm also doing a couple of small spots on the other bus while the can is open.

hambone · Post by **hambone** » Sun May 04, 2008 7:56 am

I'll have to try that. Where did you get the fiberglass stuff?
After the FREAKIN RAIN finally stops I gots some rustproofing to deal with.

bretski · Post by **bretski** » Sun May 04, 2008 11:38 am

You can get the fiberglass mat at pretty much any FLAPS or paint store. Just cut to size...

spiffy · Post by **spiffy** » Sun May 04, 2008 7:36 pm

Home Depot has the fiberglass as well.

Westy78 · Post by **Westy78** » Sun May 04, 2008 7:55 pm

spiffy wrote:Home Depot has the fiberglass as well.

That's where I got mine. They have the resin also.

Birdibus · Post by **Birdibus** » Wed May 07, 2008 8:51 pm

I'm very pleased with the POR15 and how it sinks into the rust and dries so hard. It is very thin when the can is freshly opened, and flows into every little crevice and pinhole. I'm very impressed with it.

I have read a lot about POR15 in the past, so I knew the paint would not keep very long once the can was opened, and I had a few other projects ready to paint. It goes a long way. I knew to wipe all the paint out of the can's opening, otherwise the lid can never again be removed. Eventually, by the third day and the fourth lid removal, I ended up destroying the top, but the paint had thickend to glue like consistency by then. Wish I knew what solvent would work because I didn't purchase any of the proprietary product. Be sure to have more than one paintbrush ready if you are going to be reopening the can. My brushes dried hard even though I wrapped them in plastic.

Ha! My fiberglass fabric came from a thrift store. It was 1960s era vintage house curtains, new in the package! There was a photo of a lady with a Jackie-O hairstyle, and text extolling the virtues of fiberglass fabric for curtains. I think fiberglass proved to be less than desirable for home use... I've never seen such a product for sale in recent times.

How much do you need, hambone? Zip me your addy in a PM and I'll send you a piece. Anyone else? It's not real thick fabric, but seemed to work OK for my rust holes which were not too big.

Westy78 · Post by **Westy78** » Wed May 07, 2008 10:35 pm

Was this fiberglass material woven?

bretski · Post by **bretski** » Thu May 08, 2008 7:36 am

Helpful hint for next time:

Put a double-layer of plastic wrap over the top of the can before you put the lid back on. It won't get fused-shut that way.

One other item (it's unclear from your post if you did this or not): If you don't plan to use the entire can in a single session, pour the amount of paint you will use into a separate container, and reseal the can immediately. Don't stick your brush directly into the can. This introduces moisture, which is what catalyzes the paint into that gluey mess you described.

Westy78 · Post by **Westy78** » Thu May 08, 2008 4:58 pm

Another tip: When done with the can if you have some marbles, pour them into the can to raise the level of the paint to reduce the amount of air and moisture which as Bret says is a catalyst for POR. Kind of like purging a wine bottle of oxygen with an inert gas if you aren't going to finish the bottle.

Ritter · Post by **Ritter** » Fri May 09, 2008 7:34 am

Westy78 wrote:...if you aren't going to finish the bottle.

Huh?!

Birdibus · Post by **Birdibus** » Sat May 10, 2008 10:24 am

Westy78 wrote:Was this fiberglass material woven?

Yes.

Good tips, everyone. I still have another unused can for future projects. Hmmm... forgot to load my photos into the laptop. The job isn't real pretty, mostly because of the unmatching Rustoleum baby blue, but good enough for the battery.

Ritter · Post by **Ritter** » Wed May 14, 2008 2:08 pm

Birdibus wrote:forgot to load my photos into the laptop. The job isn't real pretty, mostly because of the unmatching Rustoleum baby blue, but good enough for the battery.

I'd love to see pictures if you have the time. I'm considering this repair as well.

So, does consensus say layer of por15, layer of fiberglass, layer of por15, layer (or two) of topcoat? What about below the battery tray? Layer of por15 then topcoat?

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battery tray rust

battery tray rust