Rust repair with POR-15 & fiberglass mat

[KMOSES]

Clean up area to be patched



Make paper template for fiberglass mat



Clean and prep. area to be patched with POR-15 products



Apply three layers of fiberglass mat saturated with POR-15 and let dry



Lightly sand and apply second coat of POR-15

[KMOSES]

Apply seam sealer to patched area and paint when dry with flat black paint.

[bmwmech1]

Interesting approach... I wonder how it will hold up. The POR-15 hardens tough as nails, so I would think it should be good in a non-structural area. It looks good... Nice job!

Garey

[KMOSES]

It seems to hold up well. Because it is a modified urethane, POR-15 is not as brittle as epoxy and fiberglass resin so there is a little "give" instead of cracking.

I first used POR-15 and fiberglass mat to repair the area under my battery / right trunk well. That was almost two years ago without a problem. I have since used it to repair the left trunk well, left wheel well/ arch and a hole in the floor board.

My car was in New Jersey for the first 12 years and in Richmond until I bought it. I don't know how the guys up north manage to stay ahead of the rust that seems to get in every nook and cranny.

[woodisgood]

Think this would work on rusted rocker panels?

[KMOSES]

Are the rocker panels considered a non-structural area? If so, then it should work. Just remember to follow the instructions and if patching a hole, coat inside the hole with POR-15 before applying the patch! All the rust needs to be coated.

[Aleman]

This sounds perfect for my almost-rusted through lower rear quarter panel (beneath the antenna). Just so I got this right - there's no resin applied to the fiberglass? Just soak it in POR-15 & let it lie in the bottom of the well? This would be after scraping all the loose rust off, of course...

[KMOSES]

That is correct, you are just using the fiberglass mat and the POR-15. Sand 1 1/2" - 2" around the rust with 120 grit until you see clean metal and remove any loose rust. Make a paper template that fits the repair location and cut the three layers of fiberglass mat. Spray the clean metal with break cleaner and let it dry. The brake cleaner will soak into the rust so let it dry completely. You can apply the patch one of two ways. Using a brush, saturate each layer of fiberglass and apply them to the repair area, pressing the patch into all the nooks and corners one layer at a time (the way I like to do it) or saturate all the layers and apply it all at once. Once the patch is applied, you will need to keep it pressed in the nooks and corners until it is tacky. Once it is tacky, wait one hour and add an additional coat of POR-15 and let it dry overnight. You can then use seam sealer to dress the repair inside the trunk.

[Aleman]

Thanks for the great instructions! I think this is exactly what I need to do to stop the cancer...

[bradnic]

Sorry to be dense, but when you say to soak the fiberglass mat in por15 are you just brushing it on the fiberglass? Pics show a different color of por15 than the 2nd coat, which confused me a bit

[KMOSES]

When I say soak, I should say use a cheep stiff paint brush and coat the fiberglass mat with POR-15 and work it into the fiberglass until it is saturated but not dripping with POR-15. The photo that shows the light colored POR-15 treated fiberglass mat has been sanded. When POR-15 cures it will need to be sanded before recoating. That is why I normally recoat one hour after it is tacky.

[petrolhead]

That's just hiding the rust. The corrosion will continue regardless if it's out of sight & out of mind.

Are the rocker panels considered a non-structural area?

NO.

[KMOSES]

For metal to rust you need three things, iron, water and oxygen. By treating rust properly with POR-15 you remove the water and oxygen. The rust is stopped in its tracks. Corrosion can not continue if water and oxygen are not present.

[petrolhead]

The title says "rust repair".
Rust repair involves removing rust and or removing the corroded part and replacing it.
And this is not it. I'm not muchth for hiding rust. I've seen too much of at and I do not like it.
peace

-Jarno

[KMOSES]

re·pair-definition of;
1. to restore (something damaged or broken) to good condition or working order.
2. To set right; remedy.
3. To renew or revitalize.
4. To make up for or compensate for, as in to make repairs.

No longer rusting, no longer a hole = rust repair!