Body sand blasting or acid dipping Options

[r_towle]

When prepping a car for sandblasting, what is the common thing to do with the aluminum tags in the front trunk and door pillar?

I suppose the second question would be do I acid dip the car or get it sandblasted?

[cn2800]

I very carefully drilled out the rivets for those tags (don't forget the Karmann tag on the driver's door hinge pillar) and will rivet them back in place once paint is complete.

I've contemplated dipping the body, but have ruled it out since there's no way to remove the hot air tubes from inside the longitudinals without major surgery. I've read here that they're foil-lined cardboard. I can't imagine they'd fare well in an acid bath.

[r_towle]

I very carefully drilled out the rivets for those tags (don't forget the Karmann tag on the driver's door hinge pillar) and will rivet them back in place once paint is complete.

I've contemplated dipping the body, but have ruled it out since there's no way to remove the hot air tubes from inside the longitudinals without major surgery. I've read here that they're foil-lined cardboard. I can't imagine they'd fare well in an acid bath.

Look for threads here, McMark just cut open the longs from the outside in that area and removed the heater tube.
Give you a nice way to get access to spray in an epoxy coating after the dip is completed, then put the tube back in and close it up.

I am torn about which way to go with stripping....not sure if I want to deal with the level of work to get paint back on all the nooks and crannies that an acid bath would remove.

Also, not sure I don't want to do that....cause it's a good thing to do once and do right.

[mepstein]

I wouldn't acid dip. You'll never be able to protect the spot welded seams.

[rudedude]

Seeing the damage done to a 356 from dapo that I am restoring I would never have a car acid dipped.

[r_towle]

I wouldn't acid dip. You'll never be able to protect the spot welded seams.

After 40 years, they are no longer protected anyways.

[stevegm]

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I researched this pretty well a while back, and spoke with a company in Charlotte that does the dipping. Unless the car if very rusted, they didn't think dipping was the way to go. My conclusion was that dipping was too risky and media blasting was a better solution. Just my .02 cents.

[altitude411]

Plastic bead media blasting is the way to go in my opinion. Very gentle on the metal (doesn't pit or stress) and more control over the amount of material removed. You can leave the seam sealer intact and the media is easily removed with air. Can be used on fiberglass without removing gel coat. This is what is used on aircraft aluminum.

[rgalla9146]

When prepping a car for sandblasting, what is the common thing to do with the aluminum tags in the front trunk and door pillar?

I suppose the second question would be do I acid dip the car or get it sandblasted?

Carefully drill the two pop rivets under the front hood.
The paint/body tag on the drivers door pillar can be removed by pushing the rivets out with a lever arranged through the speaker recess.
Push them out slowly, each one a little at a time.
The rivets can even be re-used, or.... Stoddard sells them.
I'd blast it.
But tape and plug every opening or you'll have a pile of sand fall out every time you close a door.

[rick 918-S]

http://www.914world.com/bbs2/index.php?sho...=230343&hl=

I would cut the longs open and do this. The only welding you would do is replacing the outer, sill and triangles. You could use eastwood encapsolator to protect the inside of the weld area.

[balljoint]

I get sand all over the dash every time I turn the fan on to defrost the windshield.

[SixerJ]

Maybe useful background info, but unfortunately doesn't not resolve your personal dilemma

Acid dipping is big business in the UK and there are two well established companies with slightly different processes

http://www.surfaceprocessing.co.uk/for-cars.html

http://www.envirostripukltd.com/portfolio/auto-restoration

SPL have been going for years and years and have slowly improved the process and added steps, the final part being a modern ecoat which should help resolve the enclosed and hard to get to spaces which would be key for me personally. They have some potentially interesting info as to how to improve the dipping process - drilling small drain holes etc

Envirostip use an a kind of autoclave idea in the 1st instance to break paint, sealant etc down, then a much more expensive acid process to kill the rust (in comparison to SPL) which results in fewer issues later

I like the idea of Envirostip but not the fact you are left with an unprotected shell in cavities. They do etch prime, but that does not resolve the cavity issues

The blast verses dip camps are fairly polarised here

The results of long term dipping I should be able to post once I start work on my -6 as I spoke to the PO yesterday and he confirms it was dipped in the early 2000's. The closed compartments worry me as this was before the days of ecoat and protection will only be as good as getting the cavity gun in there. As she's was a race car I guess the heater tube issue did not matter

If you do decide to dip you must remove the alloy tags as apparently the acid will eat them for lunch

[r_towle]

Interesting note, the initial dip is a BASE.

The acid dip, typically phosphoric acid, is down to neutralize the base and stop the process from continuing.
Phosphoric acid also helps stop rust from continuing...same reason.

Then wash it off with water...

So the car sits for a long time in a base solution, and is dipped pretty fast into an acid bath.

Now I want to go out and weigh a small piece of sheet metal and put it into phosphoric acid for a week to see what happens.

Rich

[lsintampa]

I acid dipped....

Then por-15 the entire car...

Had to dip it twice - the first round we didn't get it cleaned in time and it started to rust again...

I've no experience with media blasting.

Acid takes it down to it's roots - that's for sure.

Sorry I don't have photos handy of the after-bath... but here's how it came out in the end.

Ended up selling it to a classic car dealer - his pro photos towards the end....

https://plus.google.com/photos/116912054149...CLGryuPK67yhzwE

[Mikey914]

I've used soda blasting to spot clean a few areas.

[SirAndy]

Whatever you do, don't use sand to blast your car.
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I found this more than 5 years later:

(IMG:http://www.914world.com/bbs2/uploads/post-179-1151215336.jpg) (IMG:http://www.914world.com/bbs2/uploads/post-179-1151215349.jpg) (IMG:http://www.914world.com/bbs2/uploads/post-179-1157310998.jpg)

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[lsintampa]

Sand will get into everything, for sure. Ever go to the beach?

Anyway, the question sort of implies dealing with only the metal - as in the body and associated parts are void of all other parts, etc.

I've heard of shops that will media blast a "roller"...... IDK, IMHO when you get to the point of asking acid or media / I'd assume it's just body metal.

If the care is that far down to just body parts, it's just a matter of choice. Either process requires a lot of cleaning up afterward.

[r_towle]

My plan, either way, is to strip it to the tub and bring it to a place on a dolly.
So it would just be a bare tub, which
I am not looking forward to....just cause it will create thousands of little projects...

Rich

[Katmanken]

And you can do the electrolysis process on a whole car too. Place in Cincinnati called American Metal Refinishing that used that process to clean some fenders and a rear lid on my teener. Parts went in rusty and painted, and came back beautifully cleaned. They even knocked the rust out of the fold at the back of the rear lid. Parts were charged and lasted for more than 6 months without rusting. Watched them haul an old model T out of their inground pool and an engine block. Looked great. Looks like they are a chain with a few more places here and there.

Doesn't go between welded seams, but then nothing does.

[r_towle]

I am starting to lean toward dipping the car, then sending it to a shop in Boston that Cevan found and have the whole thing galvanized.

I would not galvanize the removable panels, and depending upon what I find out, I may just sand off the top of the tub in prep for paint.....but then the underside and all the little nooks and crannies could be galvanized...

No idea what it might cost, but it won't hurt to investigate this.

Rich