Chemically dip or media blast

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David Austin
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Chemically dip or media blast

#1 Post by David Austin » Thu Jan 10, 2019 2:52 pm

I can see that if you chemically dip a body any internal areas, box sections, where folds meet could give later problems.

If you then dip etch prime will this not give the long term protection desired.

Those same box sections can not be media blasted and surly will corrode anyway.

This subject evokes strong opinions.

Experience seems to be the only way of knowing.

Whats your experience.

Many Thanks

David

Dan Epperly
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Joined: Thu Apr 01, 2010 4:35 pm

Re: Chemically dip or media blast

#2 Post by Dan Epperly » Thu Jan 10, 2019 3:43 pm

David Austin wrote:I can see that if you chemically dip a body any internal areas, box sections, where folds meet could give later problems.

If you then dip etch prime will this not give the long term protection desired.

Those same box sections can not be media blasted and surly will corrode anyway.

This subject evokes strong opinions.

Experience seems to be the only way of knowing.

Whats your experience.

Many Thanks

David
Wonder if chemical dip will get in between the plethora of rusty lap welds?
I imagine the only way to get rid of every speck of rust on a 356 would be to completely dismantle it, including break all the spot welds, physically remove the rust, seal and then reassemble.
Last edited by Dan Epperly on Fri Jan 11, 2019 8:16 pm, edited 1 time in total.

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Juha Vane
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Location: Vantaa, Finland

Re: Chemically dip or media blast

#3 Post by Juha Vane » Fri Jan 11, 2019 2:48 am

Anybody tried these guys?
http://www.surfaceprocessing.co.uk/
Look very good.
KTF,

Juha Vane
Finland

'59 308
'63 356
'85 911

Robert Bates
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Re: Chemically dip or media blast

#4 Post by Robert Bates » Fri Jan 11, 2019 11:24 am

I have done cars both ways. I have had 3 cars dipped, and 3 media blasted. In the end I think chemical dip is best, but there are decision points when deciding which way to go.

How badly rusted is the car? It's always worse than you think, sometimes much worse. If you are unsure, or if the car is going to stay in your family for a long time, then I would chemically dip. If the car does not appear to be overly rusty, or have excessive accident damage, then media blasting may be the way to go.

Cost may be a factor. In central Florida, to media blast a car costs me $800-1000. Chemical dip is around $2500.

Chemical dip will show where rust was in areas you did not expect, resulting in more repair/replacement of body work. You get back a huge piece of swiss cheese from the dip. But at least you can be confident the rust is gone.

In the past I have read where some have experienced "bleed" at seams with chemical dipping. This probably depends on the dipper. If properly neutralized and primed, this does not seem to be a problem. I have not seen this, but I only have about 15 years experience.

My body man complains either way. With dipping, he has to quickly prime everything. With media blast he complains of the dust.
Bob Bates
54 Speedster
65 356SC
71 911T
73 911S
73.5 911T
2003 996 Turbo

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Juha Vane
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Location: Vantaa, Finland

Re: Chemically dip or media blast

#5 Post by Juha Vane » Fri Jan 11, 2019 11:51 am

We’re doing here high pressure water blasting. Won’t deform the sheet metal,
but all paint, rust etc. is gone. But this don’t go to seams and other hidden areas.
KTF,

Juha Vane
Finland

'59 308
'63 356
'85 911

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Mike Wilson
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Location: SW Los Angeles

Re: Chemically dip or media blast

#6 Post by Mike Wilson » Fri Jan 11, 2019 6:40 pm

Robert, thanks for the info. It seems both have their pros and cons including price differential.

Mike
Mike Wilson
Lomita, CA
'63 B coupe

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Jim Liberty
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Location: Orange Co., CA

Re: Chemically dip or media blast

#7 Post by Jim Liberty » Sat Jan 12, 2019 5:59 pm

I've tried all of them, I'm back to removing by hand. One needs to be careful not to remove too much metal. …………………...Jim.
Jim Liberty

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