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Chemically dip or media blast

Posted: Thu Jan 10, 2019 2:52 pm
by David Austin
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

Re: Chemically dip or media blast

Posted: Thu Jan 10, 2019 3:43 pm
by Dan Epperly
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.

Re: Chemically dip or media blast

Posted: Fri Jan 11, 2019 2:48 am
by Juha Vane
Anybody tried these guys?
http://www.surfaceprocessing.co.uk/
Look very good.

Re: Chemically dip or media blast

Posted: Fri Jan 11, 2019 11:24 am
by Robert Bates
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.

Re: Chemically dip or media blast

Posted: Fri Jan 11, 2019 11:51 am
by Juha Vane
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.

Re: Chemically dip or media blast

Posted: Fri Jan 11, 2019 6:40 pm
by Mike Wilson
Robert, thanks for the info. It seems both have their pros and cons including price differential.

Mike

Re: Chemically dip or media blast

Posted: Sat Jan 12, 2019 5:59 pm
by Jim Liberty
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.