Dip or blast

[BobV12]

I’m in the process of dismantling a series 3 OTS RHD to allow bodywork repairs and repaint. The car is in its original fern grey paint which is not my favourite (to say the least) and there is some probably eighties rust repairs in the rear arches. Amazingly there doesn’t seem to be anymore than surface rust anywhere else which I guess sounds pretty unlikely for a 46 year old British car. I think sitting in a dry garage untouched pretty much for 30 of those years is a big reason why it’s not a lot worse.
Anyway the point is.. dip or blast?
Envirostrip use phosphoric acid which is subsequently evaporated in one of the later stages seemingly removing the risk of subsequent acid leaking onto expensive new paint. But with dipping everything gets removed down to the steel including bits I’d rather keep like the anti drumming pads on the floor pans and the red oxide primer on the skuttle area behind the dash. It’s all or nothing whereas of course blasting can be as selective as you like. However blasting has other draw backs, the need to manually remove under-seal is a big one as there is a strong risk that with the pressure turned up sufficiently to make an impact, blasting would distort and wreck panels. Distrortion even on painted panels is always a risk depending on the experience of the operator and of course does not get to surface rust inside box sections and can leave blast media in unseen places which then emerges once the car is back on the road.
A compromise whichever way but my preference is the dip as it is the neatest and most thorough does not risk damage and importantly, can have a final stage of etch priming- bare steel doesn’t last long in the British winter! I would welcome hearing of anyone’s experience of this.
Bob

[abowie]

There are endless discussions about this in other threads.

It ends up being one of those "horses for courses" decisions.

[lowact]

Latest and greatest is wetblasting. Here is video of commercial service:

You should find there are lots of companies offering mobile service, they come to you.
You should also find a lot of DYI opportunities, all you need to do is screw a jet (suction pick-up) nozzle on the end of a pressure washer, suction hose stuck into a bag of abrasive material, ie.:

Also used for cleaning grafitii off public places using biodegradable blast media, i.e. ground walnut shell, soda, etc.
https://www.ebay.co.uk/itm/Sand-Blastin ... 1698958116
Google wetblasting. You might even find this:
http://www.bridgeclassiccars.co.uk/wet- ... ing-shell/

[MarkRado]

I use guys with CO2 which removes only underseal, soda which removes only paint (also for cleaning cyl heads) and coarser media for really rusted components.

[BobV12]

Many thanks all, interesting. Note leaning towards blasting, including DIY. I was on this too other than the problem that you need somewhere to do it that doesn’t impact on garage/garden/flowers/neighbours/marriage which in my case fails on many of those. Dipping of course being an outside service avoids all of that and is a total solution- gets to every corner and removes all rust. So long as the whole car inside and out is quickly protected I think this must be on balance the better answer for me- it doesn’t follow of course that this applies to everyone. If you have to a large rural area- a farm for instance- then the decision may be different.
I intend to do this whole project myself apart the body prep, minor body damage repairs, panels gaps and painting. I have so far been delighted that everything has come undone. I recall working on a 1973 MGB which at the time was just seven years old and had to grind/cut off all fastenings underneath- the difference seems to be that the Jag’s bits are all zinc plated. Strange given the two cars are the same age and by then the same manufacturer!
If anyone needs any comment on ant part of dismantling a series 3 I am happy to help if I can, currently fresh memories and hundreds of photos.
Cheers
Bob

[Fspp369]

Hi,
I hope I may be able to help.
I used to own one of the first Sodablasting companies in UK. (Ecoblast Ltd) I had to stop on health grounds.
1: soda media will not touch rust, it makes it black but will not remove it, it’s too hard. To remove rust you have to use “doped”media (Al Oxide grit). This will remove rust but it will also create heat, this can be negated by using a water mix at the nozzle, which also reduces the amount of mess that will float around in vast amounts without it..
2: The surface of the steel will have a very good fine surface suitable for primer straight off the gun, given adequate cleaning. (CocaCola works a treat, water wash to follow).
3: Various grades of Soda are available from very fine to quite large grain size, a good analogy would be from icing sugar to lump sugar and most sizes in between. The choice depends on the substrate to be removed. Paint and filler is easy.
To do a car would take lots of media, the amount of blown dusts is high.
4: Soda is toxic to any vegetable matter it will render a lawn dead and brown in days, and it will take a long time to recover.
5: A respirator must be worn Soda (sodium bicarbonate) is not toxic in itself but the lungs don’t like if ...take it from me !!! Fingers will become crusty and dry, soda absorbs water very well.
6: If you needed, rubber, glass and other materials may be left in place on some objects.
7: Soda will remove under seal but it is a very slow thus expensive process.

I would take off most of the majority of paint with a stripping disk in house, then get it sodablasted, or possibly if you want a completely dry process, use garnet blasting to finish, then expect to spend a long time blowing media out of the corners, giving the panels a good rattle to mobilise the media whilst blowing it out, WEARING PROTECTIVE CLOTHING AND EYEWEAR.
You only come with one pair of eyes.!
Good luck keep taking pictures.