[TheCiscoKid]

I have my 38 Chevy apart.I'm new at body restoration work.Frame has been sand blasted and painted.Now I want to clear the body under side of rust before putting the body on the chassis.The body is on a low cart.I was thinking of sanding, brushing and treating with acid, but all this is over head work.I was thinking of sand blasting, but if I want it done right I usually have to do it myself and have no sand blaster.Again working over my head anyway.How do most of you do this type of job?I'm not a POR15 believer (sorry).
Cisco

[oldred]

There is no easy answer to this one if that is what you are looking for, if the body is so low that you can not easily work on it then you will simply have to raise it to make it accessible. Sandblasting or acid rust removal can both be done overhead and if you are limited to doing this yourself this is about the only options since there just is no magic solution that will easily dissolve the rust away no matter what some of that junk claims. Raise or tilt that thing to where you can easily work on it and buy or rent a sandblaster, a small one will work but even a small one will require a healthy compressor. I too am no fan of rust converters or rust "sealers" since even if they work as advertised they can do nothing for rust trapped in areas they cannot reach such as between seams. These areas will still need to be dealt with even if blasted but removing the rust and sealing with epoxy is the best way to get rid of it permanently. If a sandblaster is not an option then sanding, grinding and wire brushing then acid treat is about the only other way but be prepared for a LOT of work. If neither of these is an option then use a rust converter or POR 15 and hope for the best.

[TheCiscoKid]

thanks, that's just the kick I need.It has to be cleaned and I'll have to do it.I'm going to clean any sealer and have a go at it, but probably call a sand blaster guy come do it. Thanks really , Cisco

[Gr8 '48 bow tie]

Bead blast Yes Sand blast No. Sand blasting will more than likely warp the panels.

Al

[home brew]

You can always do what deuce did.

[PJMonty]

Cisco,

If you hire someone to come over and sandblast your car, make sure they have experience (that you can verify) blasting sheet metal on cars. Ask what media they recommend. If they say, "Sand," then thank them and find someone else. Actual sand will warp body panels, and I wouldn't suggest trying to get away with using it even on the more rugged bottom of a car.

Thanks,
PeterM

[oldred]

I have been very critical of sandblasting sheetmetal myself and I have told how I ruined my decklid and door so many times it is almost embarrassing to mention it again BUT he is talking about the underside of this thing and sandblasting this area is ok and is done all the time. Sandblasting the floor area, under-hood and door posts will not hurt a thing but you guys are right and I should have warned about blasting unsupported panels such as doors, hoods, fenders, etc since these will be destroyed due to warpage. Sandblasting is the most effective way to remove rust from this floor area although some of the other media will work too and is safer. Also just one more word of caution, whatever media is used wear a GOOD respirator ESPECIALLY IF YOU USE SAND!

Where I mentioned "under-hood" I meant the engine compartment NOT the hood itself.

[readdirections]

i sand blasted under my 68 mustang. i bought a cheap siphon blast gun with hose. i took a small container about 6" high by 12" square and filled with sand. the car was about 18" high off the floor. i ducted tape plastic onto the car and to the floor, leaving the rearend open for entering. at the front i installed a hose for my shop vac. i cut about 18" of hose from the siphon kit to use for my exhaling to keep from steaming up my hood lense. i set the blast pressure at 80 lb. i used a 4" brush to sweep up the sand and screened back to the container. i used about a 1/2 bag of sand. the floors did not warp because i used a siphoned blaster which i purchased for $10. it was time consuming, it took me 4 days. but turned out great. hope this will help you.

[oldred]

Read, Simply ingenious It is amazing what someone can do with a bit of creative thinking. I blasted the undersides of two 64 1/2 Mustangs and just recently a 68. On the first 64 1/2 I used a small home made blaster with a 3/32" nozzle and around 100 PSI, it worked great on the floor, door posts and engine compartment but as I mentioned before I ruined the decklid and one door before I learned not to blast flat areas. On the other 64 1/2 and the 68 I used a larger blaster and nozzle again at around 100 PSI and it worked perfectly but on these I was careful to avoid exterior sheet like hoods and door panels, those parts would be ruined in short order.

[TheCiscoKid]

Thanks guys.Actually the blaster guy I'm after advertises for soda blasting, but I've heard stories of it being hard to clean after.I'm thinking media blast.Any thoughts on either?
I have my car at a backyard hot rod garage.He is a certified mechanic , but he and his brother (bodyman) do not encourage me to do the job I think I should, which is get the rust off.They say POR15 the car.They think if I blast I won't have any floor left and I think if thats the case then the car needs work.The car has pin holes in the trunk and front cowls are gone.I'd rather spend time on it now than have to redo it in two years.I'm just fishing here to see if others really go to this extreme to refinish a car.
Is acid etch primer a good base after blasting?I can get in in spray cans and get the car coated fast after blasting.
Thanks guys, Cisco.

[oldred]

Cisco, I agree 100% POR 15 may have it's place somewhere but if that floor is rusty enough so that sandblasting would leave holes then POR 15 is not going to fix it. I will not say the stuff does not work and some people swear by it but what about the trapped rust in seams and other places? And the fact is if you just cover the rust you will still have a rusty floor. Good luck with your project and if you stick with doing it right you will be glad you did.

[baddbob]

Duece has some guts rolling that body on it's side. My Son and I built a flip over stand for his Nova and had it shot blasted earlier this week. The shop charged $200 and was done in two hours. They blasted the interior, floor, cowl, and inner quarters, trunk, and jambs. Rustfree now and in epoxy ready for new quarters.
[IMG][/IMG]

[kenseth17]

I don't believe you should use an acid etch primer on blasted steel. defignately not a metal prep. Think the blasted surface would make it hard to neutralize the acid. But if it is blasted there really wouldn't be any reason to use an acid product on it. Thier purpose is to eat away at small amounts of rust and etch the surface, being blasted should take care of both of those. etch primer is a 1k product, epoxy primer is 2k and will cure chemically. I would epoxy prime it as soon as possible and epoxy also will seal the surface. blasted metal tends to flash rust quickly. bodywork can be done over the epoxy, many etch primers recommend to not use any filler over or under them and would need an epoxy over the etch primer if doing so.

[PJMonty]

Cisco,

Read the thread in the forum on the SPI website:

http://spi.forumup.org/about156-spi.html

The short version is that at least one manufacturer (SPI) does not recommend soda blasting due to problems with paint adhesion afterwards.

Thanks,
PeterM

[oldred]

I could be wrong but I don't think soda blasting will remove rust anyway.