1972 Frame Sand Blast or Dipping

[Michael L.]

Hi All
Trying to get some of your thoughts. Do you'll like to Sand Blast the chassis or do you like to have it chemically dipped when you do a Frame off.
What are the prows and cons of each.
Thanks in advance

[Stephen L.]

Re: 1972 Frame Sand Blast or Dipping

I had my 67 frame chemically stripped (dipped). It turned out great with no damage to the metal surface. Even the original weld "spatter" remained. Dipping gets into all the crevasses etc. and the inside of the frame where sandblasting can't. Sandblasting also changes the metal surface. I have a chemical stripper located near me so that was not a problem. Additionally I could make out the original frame part number which had been painted over....

[Gene M.]

Re: 1972 Frame Sand Blast or Dipping

Mike,
Both methods get the job done. I've done both ways. The dip in acid will be leaching out for months after. If you are concern with inside painting then sand blasting will not get in there. Rinsing the acid off is necessary. But if you dip and don't cover with paint or something the inside will continue to rust. I prefer sand blasting, and let the inside be what it may. I figure you can't see inside and it will out last me.........

[Chris S.]

Re: 1972 Frame Sand Blast or Dipping

agree - I also have seen the acid bleed out of the seams regardless of how much you rinse it......
Blast it and powder coat it.

[Mike E.]

Re: 1972 Frame Sand Blast or Dipping

I blasted my midyear frame myself. Then primed with epoxy primer and top coated with a 2K ceramic paint from Eastwood. When I first painted it I thought it was too glossy but the gloss seemed to tone down a lot over a few months.














Mike

[Steve L.]

Re: 1972 Frame Sand Blast or Dipping

The frame rusts from the outside AND inside. Rusts gets into the overlapped seems and pushes the seams apart. It's pretty tough to blast the rust out of the overlapped seams. And you need to get the rust out of the inside of all the channels. Acid dipping will do this but it didn't get all the rust completely out of the seams. I had to pick at some of the seams to completely get rid of the flacking rust. I didn't see a problem with acid leaching out of the seams but I let the frame sit for months while I fixed the badly rusted areas. I guess it depends on how rusty the frame is. Maybe for light rust blasting is OK but heavy rust I think acid is the way to go.

POR15 sprayed inside the frame for surface rust adhesion thinned 50-50 and DP90 on the outside.

[William F.]

Re: 1972 Frame Sand Blast or Dipping

A friend had subframe and body of his '69 Camaro "dipped at the Nissan plant here in MS. but as I understand it, "dip" wasn't acid but something else. Know what this might be? Maybe I can find out.

[Mike E.]

Re: 1972 Frame Sand Blast or Dipping

A friend had subframe and body of his '69 Camaro "dipped at the Nissan plant here in MS. but as I understand it, "dip" wasn't acid but something else. Know what this might be? Maybe I can find out.

According to Redi Strip in Indy's website they call it alkaline electrolytic immersion. It does look impressive, I would have liked to try, if they were a bit closer. In one of Noland's videos he talked about their process.

Mike

[Steve L.]

Re: 1972 Frame Sand Blast or Dipping

I think the term "acid" is a misnomer that everyone uses. An actual acid would be devastating since it would dissolve good material as well.

I thought they used some commercial strength phosphate. It does dissolve rubber. I had them do my tranny x member at the same time but didn't bother removing the rubber donuts. They phoned about them to make sure it was ok to dissolve them. I said ok, they were toast anyways.

After |I got the frame back, my #3 x member had so many pin holes, it looked like a star constellation. I replaced that x member with a new one. I don't know whether sand blasting would have identified a problem since blasting is only one side. The sand blast process would not have removed the rust from the inside and I may not have noticed a problem., but I'm only speculating.

[William F.]

Re: 1972 Frame Sand Blast or Dipping

Right. Confirms what I remembered-it's actually alkaline, not acid, that new car plant uses. Don't know if other chemical dippers using "acid dip" are using an acid based dip or not, What is the stuff that some say continues to leech out of cracks?

[Bill W.]

Re: 1972 Frame Sand Blast or Dipping

Michael , I have done them both ways I much prefer dipping . I have never had one bleed . The first tank removes all paint , tar ,grease etc. the second tank removes all rust , they are rinsed and coated with a metal prep . The metal looks new when finished . I then spray with Dupont acid etching primer and flattened Imron . I dont like powder coating .

[John H.]

Re: 1972 Frame Sand Blast or Dipping

A friend had subframe and body of his '69 Camaro "dipped at the Nissan plant here in MS. but as I understand it, "dip" wasn't acid but something else. Know what this might be? Maybe I can find out.

The "dip" process in any modern assembly plant is pretty much the same - after the body leaves the Body Shop, it goes through a seven-stage hot cleaning/degreasing system, followed immediately by a hot iron phosphate (Bonderite) application, bake, then proceeds into the Elpo system, where the body is literally dipped (submerged) in primer, with the paint positively charged and the body negatively charged, followed by another bake. From there it proceeds to the sealer deck and the color system.

[Timothy B.]

Re: 1972 Frame Sand Blast or Dipping

Michael , I have done them both ways I much prefer dipping . I have never had one bleed . The first tank removes all paint , tar ,grease etc. the second tank removes all rust , they are rinsed and coated with a metal prep . The metal looks new when finished . I then spray with Dupont acid etching primer and flattened Imron . I dont like powder coating .

Bill,

I didn't know you could still buy Imron. I figured that stuff would be outlawed by now..

[Bill W.]

Re: 1972 Frame Sand Blast or Dipping

I think I have enough left for one more frame . My supplier still has some but like every thing else its not the same as the old stuff .

[Domenic T.]

Re: 1972 Frame Sand Blast or Dipping

Tim,
Believe it or not, I buy Imron (in California) for $75.00 a gallon! some say they pay $450.00 but if you use the industrial color chart (base colors) it's not expensive anymore.

DOM