Car will be on the rotisserie in a week or so. I plan on starting on the underneith body. How is everyone cleaning this area? Rolling it outside and pressure washing? Grinding with a wire wheel?

Coating the bottom:
I have seen everything from Primer to truck bed coating put on the bottom to preserve the metal. I have a gallon of POR 15 that I bought for the interior floor plans, but wasn't sure I want the bottom this shiny. Maybe DP90 primer?

Thanks

If you've got a rotisserie then by all means use a power washer. If it's greasy, a gunk treatment won't hurt either. But afterward you'll want to clean it well with a degreaser and a metal prep solvent before painting. I've heard too many negative stories about POR 15 not adhering well to clean metal. I used DP90 a top coated it with black paint (might have been Eastwood's underhood black).

If at all possible, i'd suggest you have it sand blasted, if not just go with your plan.
As far as what to spray on the undercarriage, i would go with the dp over por15 anyday..
I use spi epoxy, but the dp will do you just fine.
I used por15 years ago, but am glad that i quite using it..

What are the benefits of spi over dp?

Well dp was what i used years ago, I loved it until they re-formulated it and wen't to LF
Reason i like the spi is that it was designed for stuff like this, it has a semi gloss appearance that was designed for hot rodders, many guys will put it on their frames and undercarriages, wheel wells and just leave it as the final product.. It just has a good look..

It is very durable to things like brake fluid, i'll stop there because that is basically the worse.. lol..
But the durability is one of my high points with the product.

Your going to find that you will get alot more for your money also. 2-gallon sprayable kit is roughly around 130. Don't quote me i could be a little off.

another thing that is great about the spi is that if you strip the exterior of the body down and apply the epoxy to the whole body, it works as a great foundation for body work, I really like putting filler over the spi, and it always seemed to me that the dp would gum up. a benifit here is that you can spray the whole shell, and leave the underbody and interior alone, and then do your body work on the exterior.

I was just thinking, that if you want to see what it looks like go to my project thread and you will see me using it throughout the project.
You can see that i used it in a few different ways throughout.. even used it as a sealer before basecoat.. ever since doing this i have not seen any shrinking of any of my projects..

hope that helped.

What he said ^

Do not use the Por15 over clean sandblasted metal, it will peel right off !!! I had it happed to me and it was not for lack of prep.The reason the makers of POR tell you to paint over rust is it will grab it and stick... Good epoxy primer like Dp and you can't go wrong. If you want to use something over you still can do that as well.

Anyone ever use the new stuff called Rust Bullitt----they claim its great for the underneath---anyone with experience with this?

Anyone ever use the new stuff called Rust Bullitt----they claim its great for the underneath---anyone with experience with this?

Some swear by it... others think it's junk. From my reading, Por15/Rust Bullet/Rust Encapsulator do well in specific areas. It simply all depends on what you're wanting to use it for.

http://www.offroaders.com/tech/Rust-Prevention-side-by-side.htm

If on a rottis only one way to go... SB...but be prepared for a few holes appearing that you didn't see before...then hit as soon possible with etch primer.

capt

Anyone ever use the new stuff called Rust Bullitt----they claim its great for the underneath---anyone with experience with this?
a guy brought me in a 88 p/u to replace sheetmetal and paint, it was here about a month,, he put rust bullet on the frame, by the time it left it was already rusting through the rust bullet..

I hope nobody gets mad about this piggy back to his question. Instead of opening a new thread I figured this might help 67CamNKC too since I am in the same situation.

I saw on an old thread that some one sandblasted there car with regular fine grade sand, $6.00 for a 100lb bag. Would this be good enough to clean underneith the body. I also have to do the same.

Thanks

I would sand blast (with the 6$ sand) and then coat with Master Series permanent rust sealer. (nomorerust.com) Be aware that sand blasting does not like "soft" surface coatings like heavy grease or undercoating. I removed the undercoat from mine with a wire brush on an angle grinder. (Wear safety glasses!) Blast it then brush or spray the master series then put whatever over that. Master series only requires topcoat for UV protection can be the only coating if you want. I have some sections coated with this for years and no rust but never been wet either.

Jeff

On the camaro I am doing it had alot of undercoating on it. I used a propane torch and a scrapper to get the undercoating off. I laid a cheap 5 dollar tarp under it. It was also on a rotessiere. Be careful the tarp will catch on fire. It was real thick like 1/2" to 1/4". Then bought some MR Muscle oven cleaner off the internet. It is in the blue can. Real good stuff and dont let it get in your eyes. Then I pressure washed the floor board and it was bare metal. I had a few rusty spots to sand blast then epoxy primed it.

Standing there and scrapping was a lot easier than sandblasting the whole floorboards. Especially if it has alot of undercoating.

I saw on an old thread that some one sandblasted there car with regular fine grade sand, $6.00 for a 100lb bag. Would this be good enough to clean underneith the body. I also have to do the same.

Thanks

If you have a fresh air system, use the $6.00 sand, otherwise you are looking at silicosis exposure. It will go thru a paint resperator. There are other blasting sand (garnet) but its not $6.00 a bag

Diesel fuel works to get off undercoating. You have to spray it and leave it on for a while and spray again and wait. The undercoat gets soft and "putty-knifes" right off. I had already done (painted) my interior floors, so a torch wouldn't work. I tried to scuff my underbody and then etch and applied POR. I hope it sticks.
Good Luck,
John

I used the old wire wheel then dug out all the old putty sandblasted metal prepped and sprayed DP then re-puttied and sprayed again. Although this was 5 years ago and have not driven it, still looks great.

I used the old wire wheel then dug out all the old putty sandblasted metal prepped and sprayed DP then re-puttied and sprayed again. Although this was 5 years ago and have not driven it, still looks great.


Perfect!!!!

What is spi? dp?

So I am preparing to sandblast my undercarriage and plan the follwing process:

clean as much of the grease dirt mess off by hand, ditto seam sealer
and then blast away (with 6$ sand, respirator and hood-outside)

Then come back with a eastwoods rust encapsulator - rusty areas only and then i was going to use the eastwood chassis black paint to get that semi gloss look.

You guys are saying use the spi epoxy product instead of the chassis black? and I can also use the spi for other areas like the inside of the trunk and braces behind the quarter panels (which are removed at this time) to seal
and protect those areas?

Thanks, Matt