Chassis Preparation and Painting

[Smallfry]

Blasting will likely expose some extra holes so be prepared for some welding!

Indeed, and better to find them now, than after refinishing.

Twenty years ago, I bought a Triumph Herald from a man near Coupar Angus in Scotland (I lived in Kent) as an unfinished project. He had spent a fortune on it, and loads of time. Many components and the chassis had been powder coated. When I got it home, although the chassis looked magnificent, I found a few holes in it where is had rusted from the inside.

I had to patch it extensively, which of course spoiled the finish. Only glad I hadn't paid for the powder coating to be done.

 

[JamieA]

If it was mine and I realise that you’ve discounted it due to cost but, I would consider getting it blasted.

Please tell us more about your Seven.

I have contacted some local firms and been quoted between £250.00 and £400.00 to have the chassis blasted and primed; all grease and dirt to be removed first.

The car itself is very much a work in progress. The chassis is fully stripped and ready for attention: it needs two cracks welding, but looks sound otherwise. I have rebuilt all of the bits that go onto the chassis including both axles, the dampers, engine and so forth. The brakes are now twin leading shoe which is meant to help. I have modified the engine a little, taking it up from 14bhp to 21.

The shell, a Ruby, is shot and needs major repairs to the point that it is questionable whether it is worth the effort. If you lift the rear, the floor stays where it is. I have two replacement shells available, though, that are in better condition. One is another Ruby in good condition and the other is a Pearl, the convertible version. Both need attention, though, so I need to assess them carefully before deciding which to use.

James.

 

[bricol]

Do you want them to prime it? You have no control over how good a coating they apply. And if you need to do any more repairs the blasting exposes . . .

Does mean you need a dry day, or an enclosed transport to pick it up – it will rust as you look at it, from finger prints etc until you get paint on it.

 

[addjunkie]

Do you want them to prime it? You have no control over how good a coating they apply. And if you need to do any more repairs the blasting exposes . . .

Does mean you need a dry day, or an enclosed transport to pick it up – it will rust as you look at it, from finger prints etc until you get paint on it.

Even in a dehumidified space it will bloom fairly quickly. I welded up a series 3 chassis that had been blasted. With in a week, it needed a re blast before painting. Id personally have had it galvanised.

 

[Hotstuff]

I have contacted some local firms and been quoted between £250.00 and £400.00 to have the chassis blasted and primed; all grease and dirt to be removed first.

The car itself is very much a work in progress. The chassis is fully stripped and ready for attention: it needs two cracks welding, but looks sound otherwise. I have rebuilt all of the bits that go onto the chassis including both axles, the dampers, engine and so forth. The brakes are now twin leading shoe which is meant to help. I have modified the engine a little, taking it up from 14bhp to 21.

The shell, a Ruby, is shot and needs major repairs to the point that it is questionable whether it is worth the effort. If you lift the rear, the floor stays where it is. I have two replacement shells available, though, that are in better condition. One is another Ruby in good condition and the other is a Pearl, the convertible version. Both need attention, though, so I need to assess them carefully before deciding which to use.

James.

Thanks for sharing your build and it does sound like quite a project.

I was intrigued by your performance upgrades. I know the engines were used in motor sport so I expect there are plenty of tweaks.

Its amazing to think that these cars are almost 100 years old now but there are quite a few still in existence.
I wondered how this compares to cars made in the 70/80s.

good luck with your project and if you have time, perhaps keep us posted.

 

[JamieA]

The quotes include giving the chassis a couple of coats of etch primer to ward off rust whilst I do the repairs.

Hotstuff: there are loads of Sevens around still. There is one a couple of doors down the road and another a five minutes walk away. I know one that has about 50bhp and races at at 80 to 85mph.

James

 

[ajlelectronics]

The quotes include giving the chassis a couple of coats of etch primer to ward off rust whilst I do the repairs.

Etch is good but not anything like as good as epoxy or galvanising. If you epoxy over etch, your whole job is only as good as the etch. Would they coat it in some rubbish 1k that can easily be removed perhaps?

 

[JamieA]

Etch is good but not anything like as good as epoxy or galvanising. If you epoxy over etch, your whole job is only as good as the etch. Would they coat it in some rubbish 1k that can easily be removed perhaps?

Quite possibly. I have not spoken to them in detail yet.

 

[charlysays]

A small needle gun like a kobe compact needle scaler is your best friend. I've managed to get stuff clean enough to weld to with just a needle gun and some patience. Once you've got it as clean as possible with the needle gun then use wire wheels before abrading thoroughly with 80 grit. This will achieve ST2 prep levels which is what you need for epoxy mastics. When the needles go rounded, grind them square again on a bench grinder, really makes them more effective. I would advise wearing a full face respirator as needle guns etc generate a lot of dust and sharp metal particles and you don't want that stuff in your eyes at all. I've learned the hard way that safety specs aren't enough. Before you take off the visor either hoover or gently blow compressed air across your hair/ forehead so crud doesn't fall in your eyes.

 

[bricol]

Having done it myself, and paid others, I think a few hundred quid is a fair swap for not having to do any of the other suggested methods, not having to clean up, not having to apologise to neighbours, not having to put up with tingling arms, fingers, head . . .

 

[bert]

If it was mine I'd be having it blasted and a wash etch applied. This wont effect your repairs toomuch like epoxy will.

Then have it blasted a second time before epoxy and paint

 

[dave h 2]

I have contacted some local firms and been quoted between £250.00 and £400.00 to have the chassis blasted and primed; all grease and dirt to be removed first.

The car itself is very much a work in progress. The chassis is fully stripped and ready for attention: it needs two cracks welding, but looks sound otherwise. I have rebuilt all of the bits that go onto the chassis including both axles, the dampers, engine and so forth. The brakes are now twin leading shoe which is meant to help. I have modified the engine a little, taking it up from 14bhp to 21.

The shell, a Ruby, is shot and needs major repairs to the point that it is questionable whether it is worth the effort. If you lift the rear, the floor stays where it is. I have two replacement shells available, though, that are in better condition. One is another Ruby in good condition and the other is a Pearl, the convertible version. Both need attention, though, so I need to assess them carefully before deciding which to use.

James.

I would be more concerned about the cause of the cracks than anything else.

 

[JamieA]

I would be more concerned about the cause of the cracks than anything else.

Multiple years of abuse on a farm. The cracks are in a common place and are not structural. I gather that people often do not worry about repairing it.

 

[JamieA]

Having done it myself, and paid others, I think a few hundred quid is a fair swap for not having to do any of the other suggested methods, not having to clean up, not having to apologise to neighbours, not having to put up with tingling arms, fingers, head . . .

This is the conclusion that I have come to, as well. The price is less than expected and they are a well-established firm in the town. I shall do the repairs before the blasting and hope that no nasties are revealed.

James

 

[JamieA]

Showing my ignorance, is there anything to choose between iron oxide, silicone and crushed glass as a blasting medium for a chassis?

James

 

[Roger440]

If it was mine I'd be having it blasted and a wash etch applied. This wont effect your repairs toomuch like epoxy will.

Then have it blasted a second time before epoxy and paint

This is what im doing. Without the re-blast.

Ive done all the repairs i can see, but im sure there will be some more post blasting.

 

[Dcal]

What's wash etching?
Is that a holding primer or an acid etch?

 

[bert]

This is what I use, really thin etch primer that chemically prepares the surface for a normal or high build primer.

Lechler Fix o Dur 1lt 2k Etch Primer & 1lt Hardener | eBay

Mixing ratio - 1:1.

www.ebay.co.uk