I have searched and read the various posts on stripping a car and the debates on the best way to do that. That has led me to these unanswered questions that I hope someone may be able to assist a novice with.

Q1. How do you know if you should strip your car to bare metal or not? Is that a decision made by the person who is going to do any repairs or does the owner make that decision by thinking it is a good idea? Does it depend on the level of rust or is it a monetary decision?

Q2. From what I have seen it appears that cars are stripped to bare metal and primed before the rust is repaired. I would have thought you would repair the rust first so you can see where it is. Why is it done the other way around? Or, does the rust become even more obvious once stripped and primmed?

Q3. Most of the posts I researched were back in 2011. Has there been any consensus since then as to whether soda / bead / sand / paint stripper is the best way to go if you do strip a car all the way back. Hope this doesn't open a can of worms!

Thanks.

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Flute - 68 MK I Cooper S
Member: VMCI #2474
Member: International Mini Model Collectors Club

These are just my opinions or views on paint
Q1- Stripping back to bare metal can have a few reasons behind it. Condition of previous paint (crows feet, cracks, type). I believe the old acrylics were porous so moisture could get underneath the paint and cause it to rust. Also if you are going for a colour change, you dont want to see any of the old colour anywhere.

Q2- You should use an etch primer on the bare metal to protect it from surface rust starting. When you do your rust repair you can just cut your area out, sand the edges clean of primer and weld new bit in.

Q3- Its personal preferance. I'm not a fan of soda. If it is not completely cleaned of afterwards it can damage your new paint. Sand blasting can be a risk if the blaster goes to hard at the panels. The heat can warp them. Paint stripper is something anyone can do but it takes time. I went the paint stripper way but wish I bit the bullet and had it sandblasted. That way it would have been done quickly and easily. They can usually throw a quick etch prime on it also and then you can get onto the important bits.

Like I said, these are just my thoughts and experiences on my current resto.
Chris

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1963 Morris 850 Smoke Grey
1963 Morris 850 Shadow Blue
1965 Morris Mini Smooth Van
1966 Morris Mini Van
1969 Morris Mini Deluxe Resto
5/72 Clubman Gt

I'd ask a panel shop/painter to look at what you have. Ultimately it's your choice but proffesional advice is a good start. If you decide to blast it, then doing the worst rust first is good idea, say, replacing floor panels, guards etc, then you're not get bits blasted that'll end up in trash.You just weld in patches/panels and as Scoop said, spray with primer to protect it till final blast/prime. I had mine soda and sand blasted by pro. He soda blasts the car then sand blasts just rusty bits because if you have surface rust, soda won't touch it, soda also leaves the original etch? primer on. (the greeny coating) To do whole car + swinging panels cost $1600.

Bare metal all the way for me. The benefits are that there is no question of the condition of the car at handover to the paint shop. There is the car, devoid of paint, rust, bog deadener and its faults for all to see. The rust is gone, there are only holes and quality metal for all to see. There will be no claims later on that the job was worse than anticipated, no sucking of air through teeth over the bill, the quote will be binding.

If you handed the car over with paint on it anyway, you will simply pay the man to remove the paint for you, but not know exactly how much he took off, what he left, and how much bog. There's no honour amongst panel beaters let me assure you, they have their own children to feed, and hours are money. They may not have the same vision as you do of the finished product.

Soda blasting? I have not been convinced by any good argument that the benefits are worth the 200% minimum cost over plastic or glass bead blasting for bare steel automotive panels. The benefit to the blaster is that environmental cost of clean up is reduced, and the increased cost of product is passed onto the customer. It is more gentle than other media for historic restorations, you can see original pen and paint marks which may be significant if you have something very special.

The chance of surface corrosion forming is reduced prior to panel work starting...anecdotally...but for 40 to 50% of the cost for plastic/glass blasting, the car will be etch primed in any case. The body prepper will flap wheel this light coat of primer off as he preps the car for paint. I had my last shell blasted in Thomastown Vic for $800 seven years ago, the lowest soda quote I received was $2000.

Plastic /glass does not remove metal, it polishes the metal while it removes dirt, rust and paint. I would not recommend sand garnet blasting. Garnet has higher mass and sharper edges so is quicker at removing the surface junk through sheer grunt. But it will remove metal, etch the surface, heat and distort the panel and is just too aggressive for what we need.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

What about the process used by Minus Paint? No risk of distortion, but I am not sure if it starts to attack good steel if it is left in too long.

From the web site "Minus Paint has the largest Alkaline tank in South Australia, large enough to immerse an entire body shell". Can take 7 to 8 days and they can metal etch it.

http://www.minuspaint.com.au/

I am looking at options for the Monaco, but not sure about the fibre glass roof. I would cut the worst of the rust out before doing anything - why pay someone to blast a hole that you know is there?

It's not always obvious what's rust and what's not, especially when dealing with a surface that is uniformly pitted. If you blast it the "grey" areas where the pits don't look too deep by the comparable surface around may yield greater rot. I guess that depends on what pitting/rust you are willing to put up with.

The issue with chemical dipping is getting it out of the seams and box sections afterwards. Same with sand or soda except capillary action won't drag sand inbetween the spotwelds. And the fibreglass roof is likely polyester resin, I'm sure the dippers have had that question before so I'd call them and ask.

Me? I'm cutting the majority of the rust out, the flinstone floor, a bulkhead section where the pits have eaten through, rusty wings , will closing panels and rust around the rear valence.

I stripped the car took a stick of soap stone and marked all the areas that needed work, then wrote them up on a whiteboard. When they're all solid it'll be media blasted sans outer sills, as the closing panels rotted through. Then out comes the soapstone again....