Joined: Jun 2018 Posts: 541 Threads: 95
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After a long hiatus, I have managed to get back to rebuilding my Seven. I am currently starting on the chassis which needs a couple of minor repairs, but otherwise just needs cleaning and painting.
I intend to clean the chassis up with wire brushes on the angle grinder, along with scrapers and anything else that I can get into the nooks and crannies.
I am conscious, though, that there are some sections that will be difficult to clean as thoroughly as I would like. I was wondering what other people do about these areas and what sort of treatment they use to prevent rusting, prior to painting. I intend to use some sort of chassis black paint, but I am not sure which one yet.
Any suggestions would be appreciated.
Jamie.
Joined: May 2018 Posts: 2,143 Threads: 111
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Location: Llandrindod Wells
Car type: 29 Special, 30 RK, 28 C Cab
Hi Jamie
If you can afford it, I would recommend a blast clean followed by sprayed primer and then any chassis paint you fancy. Shot blasting will get into more nooks and crannies and have the advantage of showing up any serious corrosion and loose rivets. There is a wise saying “paints are only as good as the surface you put them on”.
Cheers
Howard
Joined: Jun 2018 Posts: 541 Threads: 95
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Thank you for the replies. Ideally, I would like to do this myself due to cost. I do have a small sand-blasting gun that I picked up. I had wondered about using that, with the right type of grit, for the inaccessible spots. The mess puts me off, though.
The dry ice blasting looks impressive, but with a starting price of £250.00 per hour, more for classic cars, I do not envisage going down that route.
Jamie.
Joined: Oct 2017 Posts: 1,577 Threads: 58
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The problem with blast cleaning is it has to be painted immediately because it will start corroding immediately with our climate. I once had a body cleaned in this way collected it as soon as it was done on a nice hot June day and on arrival at home within the hour started spraying Deox C on it and i could see it removing the surface rust film.
Joined: Aug 2017 Posts: 3,451 Threads: 108
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Location: Darkest Bedfordshire
I'm not sure if it's still available but at one time you could get a frame blasted then hot zinc sprayed.
The frame on my Ulster rep was done this way circa 1980.
Last time I looked at it everything still seemed pretty solid, I just freshened up the paint.
Of course if shot blasting or coating you need to remove or protect ALL the moving parts e.g. brake cross shaft.
FWIW I'm not a great believer in magic paints, the preparation of the surface is more important.
If you apply e.g. Hammerite to a freshly shot-blasted surface (wipe the dust off) it will stick pretty well.
As Dave says, get a coat on straight away.
Joined: Aug 2017 Posts: 500 Threads: 15
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Location: Dunchurch, Warwickshire
I know it's a bit more expensive, but I went the bead-blasting & powder-coating route with my Cup's chassis. If you do this, it is highly recommended that you choose a company that will blast and coat on the same premises in order to get the paint on as soon as possible after cleaning (as Dave mentions above).
Joined: Jun 2018 Posts: 541 Threads: 95
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Thank you for the replies and suggestions. I have contacted a few local blasting firms to see what their potential prices will be.
I tried my sandblaster: lots of mess, lots of noise and no difference on the rust.
Jamie.
Joined: Aug 2017 Posts: 1,047 Threads: 55
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Location: The delightful town of Knaresborough, North Yorkshire
Forty years ago I completely dismantled everything including brake cross shaft and took the bare chassis to a blaster. Shot blasting can be too aggressive for thin metal and the whole thing could be distorted. Grit blasting is best for a 7 chassis. My bare chassis could have been put through a blasting mill on a conveyor for free, where father in law worked, but I was advised against that. So I got this professional blaster to grit blast it. can't remember the cost, but with a new mortgage and 2 young kids and a stopathome mum, the price can't have been too bad. We collected chassis and it looked very clean and vulnerable. Rushed home with it and brushed it with an anti-rust primer. Sprayed next with a couple of coats of cellulose primer filler. Then sprayed with celly black gloss. Chassis was then put on one side for well over thirty years in a large garage with dehumidifier. About six years ago it still looked perfect and glossy. It was then built up into a car and I've still got it. Been driving it for four years or more.
