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MG Midget and Sprite Technical - Chassis Advice

Hi,

I am looking for personal experiences here and not general opinions if that is ok with everyone!! ;-)

So I am looking to make a decision on the best approach for the next phase of my restoration, fixing my chassis.

Initially I did consider manually tackling each rust patch with tools and rust converters, but there are so many patches of rust with different degrees of corrosion (mostly very minor), trying to find them all and treat is going to take ages.

That leaves me with two parts to this;

* Dipping or sand blasting followed by epoxy priming and

* Sorting out the irreparable rust, like the sills and floors.

I am trying to work out which is the best route to take. Money is not the factor in my decision, as it comes down to the best approach.

So two questions:

1. Should I get the bulk of the chassis sorted in one go and then tackle the sills and floors or the other way round.

2. Depending on the order of events would you dip or sand blast followed by epoxy priming.

Many thanks in advance.

James
J Paul

If you say "tackle the bulk and then go to floor and sills" I want to suggest a reshell....

You need something to tack all the new metal on.
Some pics would be a good starting point
Onno K

Onno - you just need to find a good point to start with

Anywhere where more than an inch of good weld should be enough to get you going.

I personally would go the route of getting floors, sills, etc all built up and welded and nice and square, then work your way up from there being able to mount the good remains of the shell to a solid base.
PeterJMoore

Hi Peter,

I think that is what feels the right thing to do as well. I just have to focus on that and not look at all the minor surface rust, dirt, old paint, oil, grease, etc... for now.

Although the sections that need the most attention are quite bad, the extent of each bad patch is isolated to a small area.

I am lucky as there is plenty of good metal to weld to, I just have to find it under the years of crap.

Thanks

James
J Paul

I agree fully with Peter J Moore, thats what was done on my 1500 - are you then planning on having it blasted afterwards? - Blasting is expensive... repair panels aren't cheap either... if its really that far gone, I would seriously consider a new bodyshell... they are relatively inexpensive and would save you so much time.

As you say, money is no object.
C L Carter

I wouldn't say that shells are relatively inexpensive - not anymore. They might have been a few years ago but at about £6K unpainted you can save a lot of money by having a go yourself.

Having said that I would go through the car and do a costing of all the panels you require. I've just done that on mine and spent £660 at Moss - the bits that worked out cheaper than anywhere else after the 15% off. I think I've got most of the panels I need but I left the A post as I won't know how bad they are till I strip the doors and wings off.

It might be a good idea to keep a look out for a shell in better condition or even a complete car.

Regarding shell prep I think I am going to clean mine up myself with paint stripper and a lot of scraping and sanding. It's hard work but unless you want show standard underneath it's not always necessary. It's how I did my Sprite a couple of years ago - I'm not looking forward to doing it again though! I also think blasting can sometimes take things back too far. I might just get the removeable panels done by having them dipped to save time.

Like you James I'm unsure on how to start on the repair work. I've heard conflicting advice. One is to do the sills before anything to get the strength back, the other is to do everything (apart from the floors) then sills last. Both said to leave the floors till last. My problem with the first option is that there is nothing to weld the new sills to!!



John Payne

***My problem with the first option is that there is nothing to weld the new sills to!!***

Combined with asking the question your asking of the bbs....

Im liking Onnos advice ...

for 6k, your getting alot of benifit...you can have the new shell delivered straight to the paint shop for paint and id bet it would be ready to reassemble in a week ...while its being painted you can be removing parts and restoring them....you could have a brand new midget in a month....a huge time savings, and probably not that much more expensive then stripoing, epoxing priming, reinforcing the shell, cutting out the bad, all the patch welding...and thats if you got all the tools to do the deed, if not a decent gas mig is $2500 to $3000 easily... Yes you can get a china basic mig for $100... Ive got one, its great for pluging exhaust holes and welding up screw holes but NOT for the type of work your needing to do

Id also lok at a plasma torch....very cool and a big plus

Yes another used car is an option, but how hard will it be to find a rust free midget shell....maybe complete rust free complete midgets ready to drive, so whats the point of stripping it down to change these parts over....if thats the option, then strip this car and part it out on ebay.

Opps ... I posted my opinion, sorry about that

Prop
Prop and the Blackhole Midget

On the Mini I replaced any obviously rotten panels, and all the revealed rotten panels behind them, and the ones behind *them* as well. Then I test-fit everything, attached all the brackets and drilled all the holes for insertion of waxoyl, and made sure the doors and bonnet fit properly.

Then I had the whole thing caustic dipped, rinsed, and dunked in etch primer. A few new patches of perforated panel were revealed, but nothing like as scary as what I would have seen had I dipped the shell before doing any work.

My main reason for doing it in that order is that it's very humid here, and even etch-primed metal will begin to rust after a month or so. I was pretty sure the Mini shell would need more than a month's worth of work!
Growler

I think that the first consideration is whether you enjoy the actual work involved in repairing a bodyshell. Or is the work involved just part of a means to an end, and what you are really, impatiently, wanting is a running car. If the latter then maybe look hard for a good condition shell to start off with. This may seem an odd view, but I actually enjoy the repair work at least as much as driving.

I also think that there is less difference than might appear between a basket case body and one that is just looking a little frilly round the edges with bubbling paint along the seams and around the hinge pillars. The reason being that in both cases to do the job properly major panels like the sills need replacing as a single piece. So whether the rust is relatively minor, or very severe, the work is the same. An argument for being brave and tackling severely rusted bodyshells!

I would start with the footwell sides. They are easy to do with nice dimensions and angles to set up. And much of your welding will be hidden later. A good place to practice as so as long as it is strong it doesn't have to look pretty! They are likely to rust out where the panel joins the top of the inner sill and at the outer end of the triangular box section that forms the toe board. Get this front corner built up and you then have something to build the new outer sill to (and inner if it is that bad) Then do the sills and any repairs to the rear box section/ spring hangers. Then floors.

Keep the price down by making as many of the panels that you can. Flat panels and simple folds and flanges are easy to do and chances are that you can get the steel for free or next to nothing from the scrap bin of a local metalworks business.
Guy W

I think Guy's suggestion of starting with the footwells sounds good. James seems to relish the challenge of doing the work to his car which is why a lot of people set out on these restorations. Also it means you can spread the cost of having a decent car without having to buy a £8000 re-shelled car outright. Of course if all you want to do is drive then the latter is the best option.

Guy have you any photo's of your restoration work? I've been looking at the ones in the Haynes restoration manual and they aren't all that clear!
John Payne

Yes I have photos. But the ones of the first two restorations pre-date digital cameras. Or at least my ownership of such new-fangled devices. Lots of photos of my current Frogeye restoration, but which ones to post here? !

Better is the amazing set of photos of this fantastic work:
http://www.cardomain.com/ride/2203663/1961-austin-healey-sprite/1967-mg-td/

Guy W

Hi Guy and John,

Thank you for your excellent advice based on your own experiences.

Certainly the aim is to restore the car and not to rush to have a finished example.

I agree that doing each area at a time is the best way forward and I also don't see how I can end up spending the thousands being quoted here. Moss and Sussex sell all the panels I need at a fraction of those costs. £100 will get me enough panel to finish 5 different areas. I was looking at spending about £75 per month, to get a panel or part here and there.

Hi Prop, I am lucky to have been lent a MIG welder and some gas. I want to give this a go and I will. I have friends who can help me out if I need it, which will be invaluable.

Growler, thanks for confirming what John and Guy (and others) have been recommending to get on with the repairs and worry about the surface rust later. But I did notice that ( for the second time) someone has had there chassis acid dipped before welding new panels on. It just seems to make the job easier to focus on each section.

Just working out where to start the cutting out of the damaged areas should give me practice on removing old coatings, So i'll take it from there.

Getting my first grinder for Christmas which I plan to have fun with!

Many thanks guys, you have renewed my motivation and suppressed my self doubt!!

James
J Paul

Cheers Guy, thats helpful, especially as its a 1/4 eliptical car.

I've just found this place about 20 mins away from me:

http://www.prostrip.co.uk/car-auto

I think I'll get a quote!
John Payne

James,
my experience is it's best to repair the major rust sections first eg the full or part panels you intend to replace to get the shell to a strong core. This is needed to ensure it doesn't warp when handled to/from the "stripper". Leave the light rust areas, underseal etc to the stripper which should remove them and other rust area's you thought were okay!

My replacement B shell was in reasonable condition to start with and went for a dip before starting work as it was passing the door on the way to me. See in the picture the result of a good strip but v.bad application of the protective coating... this was taken after the rot was replaced (hence the new sill and arch) just before it went back for a second "unplanned" dip to deal with the flash rust. Thankfully it came back in much better shape the second time. To make sure it did I visited the stripper to inspect it before dispatch which added an extra few hundred to the cost :0(
When you get it back from stripping get a coat of epoxy primer on as soon as possible and then deal with any new holes uncovered (and there will be some!).

Best of MGmike





M McAndrew

and one with the primer on. note the holes on the castle rail end plate. These only came to light after the first dip and will be replaced before stone chip and paint is added.

MGmike




M McAndrew

I think the very 1st thing id do is a total wash and clean...so its perfect clean... Uou mentioned there was dirt, grease and oil in various places

To remove old paint primer and bondo... Try acetone and a green kitchen scratchy...that will take it off to bare metal fast....chemical gloves.work great.... You can get acetone by the gallon cheaply at any good house paint store

Prop
Prop and the Blackhole Midget

I work my way round, and only focus on one section at a time, or the job just gets too daunting. I would do all of the bodywork repairs first, then send the whole tub off for stripping if that is an available and affordable option. Then expect to do some additional minor welding on any some bits that might be exposed. But in reality it is very easy to tell where the rot extends to, cut it out. Try tapping around with a small toffee hammer and the rusted bits will sound different to good steel.

Don't go mad with your new angle grinder! Only cut away around one bit to be repaired at a time. Work on one side of the car and leave the other untouched so you have something to check measurements against and it also helps retain the shape. DON'T take the doors off as they provide the critical angle between the A post and sill and then between the sill and B post. Surprisingly, you build the car around the doors, you don't fit the doors to the car. Brace the door openings before cutting out the remains of sills and preferably support along underneath the car on a good length of 6" X 2" timber or steel joist.

Get some 1mm wide slitting disks for the grinder. Much better, quicker and cleaner cut than standard cutting disks. Target price around £1 each Sometimes available at Aldi, and certainly online at this.(don't pay Halfords / B&Q prices!!)Flap disks are better than grinding disks as well and give a nice controlled finish. The nylon pad stripping disks are great for paint but avoid sharp edges or they wear really fast!

For welding information and supplies well worth looking through this site:
http://www.mig-welding.co.uk/
Guy W

This is my approach

Have no recent pics though, but its all welded together and thrown in the corner of the garage until the room is available to start into it properly again.


PeterJMoore

Again, rusty panels - cut out and weigh them in.




PeterJMoore

slightly later pic that above with tunnel started from scratch too




PeterJMoore

Guys, thanks again for all you advice. Each of you has made some really good points here that will be invaluable to me in the coming weeks.

Hats off to Peter that is some project you have! Fairly sure mine is no where near that bad, but I could be proved wrong!!

Many thanks again

James
J Paul

Yup I agree.

Peter has a big job to do there. Not so much a restore or rebuild, it looks more like a build a Midget from parts from the ground up.
Lawrence Slater

I've just had a quote for dipping the shell of my Midget. I got one quote for the whole shell and panels and one for just the panels - doors, wings, front end, bonnet and boot. Whole shell is £1050, panels £450.

A bit too steep for me I'm afraid!

John Payne

John,

Soda blasting would be half that price

Normal media blasting would be cheaper again

Soda blasting for me is a personal favourite. But i have been seeing a lot of cars being turned out by that Surface Processing company on facebook and their dipping looks fantastic.

What I would probably do if funds permitted is have it soda blasted, that way you know where the good steel is, carry out all the metalwork and repairs until you are happy that it is complete, then get the likes of those guys to electro-dip it with that E-Coat.

Would then have the same protection as pretty much every new car on the road.
PeterJMoore

Hey peter

Im a fan of soda blasting... But i didnt think it did well on rust

You can get china made soda blasters cheap... I got one from harbor freight several years back for like $100 but you need to have a big donky compressor to really get the most out of them... Cause they love to eat lots of air

Id becarful with walnut or sand medium, cause you can get into some warpage fast.

Just a thought... Do one section as a goal per night...aka the right fender... That way with in a few weeks yoy can get the entire car dine easily... If you try and do the car all ar one time... It just becomes to much and burn out sets in fast, then you got a 20 year garage space occupyier

Trust me.. im speaking from experiance. Ask me about my cly head thats taking 1 year and several months at this point....(sigh)


Prop
Prop and the Blackhole Midget

Hi,

I had a quote for sand blasting and epoxy primer for £350 to £400 for the whole chassis. I thought that was fairly reasonable.

For the avid DIYer here is a home made soda blasting kit:

http://www.aircooledtech.com/tools-on-the-cheap/soda_blaster/

Regards

James
J Paul

Prop - it removes rust, leaves metal, unfortunately it doesnt remove weak metal which is why it is preferred on older shells and chassis as it is very non-destructive in comparison to other media blasting.

James, that sounds about right, but I would ensure they dont blast the large flat areas in the middle of panels as they will warp.
PeterJMoore

This thread was discussed between 17/12/2012 and 20/12/2012

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.