I am looking into either doing a chemical dip or media blast to remove paint and rust. Currently I am trying to determine what are some of the practical problems and solutions to dipping the car (I am aware of the concerns about acid leaching into the paint at a future date if the dip is not done correctly). Anyhow, as part of this I have some questions (mostly issues with doing the dip)...

1. Can the DOT sticker be removed and reapplied (such as via razor and glue)? I know that official replacements can be obtained from Porsche, but they don’t replicate the original look. If possible, I would like to preserve the original sticker.

2. I assume you can remove the rivets from the Karmann plate in the door and the plate in the front trunk prior to the dip and then try to find correct replacement rivets to put them back. Is there any problem with leaving the VIN plate in place?

3. I think I read somewhere that if you dip the car you need to open up the longitudinals to remove the heater tube as it is made out of cardboard. Can someone verify that this is correct?

4. Other than needing to remove everything from the steel body (wiring, trim, gaskets, etc.) is there any other prep work that would need to be done prior to dipping the car?

5. A local vendor gave me a rough estimate of about $1200 - $1300 to dip the car. Is this in the ballpark of what I should expect?

6. I haven’t contacted anybody yet about the cost to media blast the car. How much should I expect that to cost?

Thanks

Richard

Richard-
What's up? Are you going to the THSCC Xmas party?? Hope to see you there.
Anyway, here's the results of a quick search on acid dipping, some pretty detailed threads. Pay attention to the threads on pg. 5 posted by Brad, your longitudinal questions should be answered.

http://www.914world.com/bbs2/index.php?act=...opics&hl=&st=80

in some states you a supposed to get written permission to remove the VIN plates for restoration....I have read on the web of an MG guy getting his balls busted over it (used like the wrong rivets or something that really stuck out)

QUOTE (Mueller @ Dec 6 2005, 10:47 AM)

in some states you a supposed to get written permission to remove the VIN plates for restoration....I have read on the web of an MG guy getting his balls busted over it (used like the wrong rivets or something that really stuck out)

Speaking of the rivets, where can I get the ones for the Karmann plate? They're a round headed rivet I can't seem to find locally.

I don't know if SirAndy will chime in or not - but he had his car media-blasted and has had ongoing problems with the media falling out of various cracks and nooks pretty much ever since. IIRC he said to me that dipping is the way to go.

There was the guy in Massachusetts, William Harris(?), that had his car blasted with baking soda. Seemed quite pleased with the results. The baking soda pretty much just washed away.

QUOTE (fiid @ Dec 6 2005, 11:54 AM)

I don't know if SirAndy will chime in or not - but he had his car media-blasted and has had ongoing problems with the media falling out of various cracks and nooks pretty much ever since.

yes, i'm here ...

- the sandblasting sucked! the result was *ok* but now, after 3 years or so, i still have sand creeping out of the cracks and i need to clean the interior and trunks every 4 weeks or so.
it get's everywhere! i taped up *every* hole in the engine comp with duct-tape as i didn't want the engine to suck in any sand.

- for the acid-dip, you'll need to cut the longs open and get the heater-mufflers out. they will *not* survive a dipping and replacements are NLA.
there's a very good thread about how to do that from Brad Roberts, i believe it's in the search results posted above.

- you'll also need to remove ALL of the round hole covers in your trunks and floorboards.
if you don't, the weight of the acid in the trunks and cabin will bend the tub when it's lifted out of the bath.

- also, you should weld in large dia. door opening support beams. they help two-fold. first, the prevent the chassis from folding when it's lifted out of the bath and secondly, they give the dipper an attachment point to lift the car out of the bath.
this is also shown in one of Brad's posts about dipping the blue /6.


Andy

QUOTE (jdogg @ Dec 6 2005, 01:44 PM)

Richard- What's up? Are you going to the THSCC Xmas party?? Hope to see you there. Anyway, here's the results of a quick search on acid dipping, some pretty detailed threads. Pay attention to the threads on pg. 5 posted by Brad, your longitudinal questions should be answered. http://www.914world.com/bbs2/index.php?act=...opics&hl=&st=80

Jason,

Hey, yeah wife and I will be there. There is no way I am going to miss out on picking up my 1st place year end trophy.

Thanks for the search results. I will dig through those. I have done some searching myself and I don't think I have found a solution to the DOT sticker one yet.

I'm going to be doing the baking soda blasting, and they told me to remove the undercoating before bringing it in, as it really slows them down and they charge by the hour. I'm pretty sure that the undercoating needs to come off no matter what method you use... or at least it helps. Soda blasting generally leaves seam sealer intact, so any that you want to remove would have to be taken care of beforehand if you go that route.

Thanks for the help everyone. I found Brad's various threads and have read through them. What I have gathered so far...

* You do have to open up the longs (no biggy, I want to see the condition inside anyhow)
* You need to reinforce the tub to prevent it from bending. (Was planning on bolting in something between the door hinge and the seatbelt pickup point, but welding something in might be better and stonger if they use it to lift the car)
* You need to remove the plugs to allow the fluid to drain (Didn't know that)
* You need to remove the seam sealer and undercoating in advance (Didn't know that. Yuck! I was hoping I wouldn't have to do that)
* You need to find a way to seal the empty cavities once you are done. (Was planning on doing this, but wasn't sure how. See question below)
* I am assuming that the dip will not damage the VIN plate (will verify with whatever vendor I use)

Remaining questions...

1. Has anyone been able to remove the DOT sticker without destroying it? In the photos of Brad's car, I think I can see that the sticker has been removed and that there might be a trace of adhesive left behind. His thread doesn't (or any others that I can find) mention anything about dealing with the sticker. As that car looked to be a total resto, I assume the owner wanted the original DOT sticker put back.

2. Regarding sealing empty cavaties. I was thinking of spraying in POR-15 and then after that maybe a "Cavity Wax". Or is the combo overkill? I am at least going to do POR-15.

Por-15 doesn't work that great on bare metal..it needs a bit of rust to get a good bite. RM or PPG epoxy works good without a top coat or vinyl wash with a topcoat. Look at my bus in my blog...RM epoxy.

The VIN plate is aluminum...acid will destroy it for sure. The sticker is history.

All 3 data plates are aluminum and will not survive an acid dip.
Never knew of a succesful decal removal, it always tends to fall apart, and it was designed that way.

QUOTE

2. I assume you can remove the rivets from the Karmann plate in the door and the plate in the front trunk prior to the dip and then try to find correct replacement rivets to put them back. Is there any problem with leaving the VIN plate in place?

Well I just went through this w/ LE tub using plastic. I had taped that plate up pretty well but it still got wrecked. I should have removed it but I couldnt locate ther rivits you mention.

As for media continuing to "weep" out of the chassis, right now it in the garage on stands and some of the grinding and banging has resulted in some plastic "fall out" but not a substantal amount. I guess it better than sand

Does any one know where to get those rivits?

Also check with the dip company, most of them prime the whole car as part of the deal. After baking (to get any leftover acid out) it can start to rust right away, so it's often part of the package.
Most use a special red oxide sealer primer.

If that's the case you just need to put a topcoat on to seal it.

QUOTE (Richard Casto @ Dec 6 2005, 02:21 PM)

* You need to remove the seam sealer and undercoating in advance 2. Regarding sealing empty cavaties.  I was thinking of spraying in POR-15 and then after that maybe a "Cavity Wax".  Or is the combo overkill?  I am at least going to do POR-15.

actually, seam sealer *will* come off during the dipping, undercoating will *not* ...
if you leave the undercoating on the car, they will have to remove it first and they'll charge you a premium to do so.
seam sealer is not problem thought and it's actually nice to have the seams exposed as there is often rust hiding under the seam sealer.

as for the cavities, POR-15 alone would be a poor choice. you want to coat everything with "Metal-Ready" and then may apply POR-15 on top of that.
metal ready is what really works with the metal.

also, have them primer the car as soons as it get's out of the neutralizing bath as otherwise the bare shell will start to rust within a day or so ...
it'll only cost a few bucks more for the primer, but it's worth it ...

Andy

QUOTE (SirAndy @ Dec 6 2005, 06:00 PM)

QUOTE (Richard Casto @ Dec 6 2005, 02:21 PM) * You need to remove the seam sealer and undercoating in advance 2. Regarding sealing empty cavaties.  I was thinking of spraying in POR-15 and then after that maybe a "Cavity Wax".  Or is the combo overkill?  I am at least going to do POR-15. actually, seam sealer *will* come off during the dipping, undercoating will *not* ... if you leave the undercoating on the car, they will have to remove it first and they'll charge you a premium to do so. seam sealer is not problem thought and it's actually nice to have the seams exposed as there is often rust hiding under the seam sealer. as for the cavities, POR-15 alone would be a poor choice. you want to coat everything with "Metal-Ready" and then may apply POR-15 on top of that. metal ready is what really works with the metal. also, have them primer the car as soons as it get's out of the neutralizing bath as otherwise the bare shell will start to rust within a day or so ... it'll only cost a few bucks more for the primer, but it's worth it ... Andy

Andy,

Thanks. Yep, I was going to use Ospho or something prior to the POR-15. I haven't spent much time talking to the local shop that does the dip, but they mentioned they usually will spray down the car with Ospho. He didn't mention painting it. Either way, I will make sure it gets some type of Ospho like treatment and if they don't put down a primer, I will.

I just really don't want to spend the $$$ doing this and then have the car still rust from the inside out.

Aside from Andy's issue with media blasting (leftover media), my biggest issue with media blasting is that it doesn't remove the crap they put in the top front and rear corners of the rear fenders. Nearly every 914 I've worked on has had rust issues in this area. Any full restoration I do absolutely MUST have those areas cleaned out and checked for rust. Acid dipping takes care of it. But you'll have to get up there with pokey tools or fire to get it out if you media blast.

QUOTE (McMark @ Dec 6 2005, 05:19 PM)

my biggest issue with media blasting is that it doesn't remove the crap they put in the top front and rear corners of the rear fenders. Nearly every 914 I've worked on has had rust issues in this area. Any full restoration I do absolutely MUST have those areas cleaned out and checked for rust. Acid dipping takes care of it. But you'll have to get up there with pokey tools or fire to get it out if you media blast.

found the thread ...

http://www.914world.com/bbs2/index.php?act=...t=ST&f=2&t=3676