Welcome to our resource for MG Car Information.



MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - Body Tub Modifications. Guy?

Guy in an old thread (Body Tub Modifications, 2008) you wrote --- :
"Fill the narrow cavity between the boot floor and rear wings up to the level of the floor with resin and seal off with seam sealer (sq bodied Sprite)

Same treatment for the triangular cavities at the back of the rear wings and across the down-turned joint between the rear floor and rear valance. All brought up to a level with the floor so there are no water traps that don't dry out.

Weld a 30mm wide strip around the lower rear edge of the rear inner arches - it acts as a drip rail so that water and mud is shed off rather than blasted up under the rear floor."


Can you elaborate on the 30mm wide strip; do you have a picture? What resin did you use for the filler? Was it a liquid that you poured in, and then sets hard?

Whilst I'm having to repair some of these sections on the midget, I might as well incorporate some improvements at the same time.
Lawrence Slater

Now that's potentially a big topic!
I was rebuilding my "Sprite beyond the grave" during the early 1990's. Although its now been on the road since 1996, its hardly a basis to draw any firm conclusions from! My previous 1500 had rusted through sills, A posts, spring hangers etc at 11 years old from factory new. So my rebuilt Sprite is doing a lot better than that, but how much of that is due to the various body modifications I did when rebuilding the tub, who can say? There are a lot of cars out there that haven't rusted out to that extent, and haven't "benefited" from the modifications I did either. So who knows!

Not sure that there is much more to say about it than you have copied from that post of mine 5 years ago. I filled the "crevasse" between boot floor and rear valance pretty well flush to the boot floor with seam sealer (not resin). 18 years on it hasn't rusted from the inside (as they often do) but if repeating I would seam weld along the bottom edge of the joint to waterproof it from the outside as well, rather than just spot weld.

I was rebuilding the inner rear wheel arches, so I extended these down below where they join the boot floor, by around an inch to form a proper drip rail behind the wheel well. Maybe they were all like that - is it supposed to be a down-turned flange anyway? Seemed like a good way to shed the water off the inner wheel arch at the back. Those edges were all seam welded, which does appear to have worked much better.

I think the biggest single rust preventative challenge on these cars is to get a good paint coating on the insides of all the box sections. Certainly not an easy task and although I have tried various methods, I don't have a solution for that one!
Guy W

Thanks Guy.

What about the "narrow cavity between the boot floor and rear wings" ? Can you tell me what resin you used in there to level/fill the cavities? Was it a liquid that you poured in, that then set hard?

I've considered welding a stip of metal along that crevasse between boot floor and rear valance. What's ot for? My guess is it was meant as a kind of collection point for any water in the boot, that would then drain through the small equi-spaced drain holes. Clearly a bad idea given how it rots there. I guess a really good couple of coats of paint a even body filler would do the same job.

I agree with you about the paint too. As long as the metal is coated, and then adequately drained with holes, or kept dry, it won't rust. That's one thing I've discovered about this Midget. It was covered in ziebart, directly over the new unpainted body panels. I can now see that it was ziebarted after some kind of repair or restoration. I'm pretty sure that's why it rusted in the same areas again.
Lawrence Slater

Do you know Lawrence, I cannot remember! It was 18 years ago! Pretty sure it was liquid and I poured it in. It set hard. I only did one side.

I have just this last week had to cut out and weld in a new 3" wide patch on the side that I didn't fill! Although there appears to have been an additional factor involved. When I sliced through the outer panel and peeled it away, I found about 4.50 in assorted coins wedged in the bottom of the crevasse. They had accumulated a lot of grot, blocked the drain holes and caused the bottom of the panel to rot from the inside out. So I blame the coins!

Of course, had the space been filled with something, I wouldn't have lost my money down there in the first place!
Guy W

Curiously, the MGB has a drip rail at the back of the rear wheelarch.

Dave O'Neill2

Cheers Guy. I found 20p in the Midget. Given the rust, I reckon I should have found much more.

That's a good pic Dave. Yup, I think I'll do something like that.
Lawrence Slater

<<Given the rust, I reckon I should have found much more>>

The rest probably fell out through the holes.

<<That's a good pic>>

Thanks, I've found an easy way to photograph the underside...

Dave O'Neill2

Do you have to drive it like that to get it out through the workshop single door?
Guy W

Hey lawerance

Several years back there was a device you could hook up to the car that allows electrical current to flow through ...the idea was it wouldnt allow rust to form onbhe car not sure what it was called, but always seemed like a good idea at.the time. Might be worth an wasnt all that expensive ither... granted a little more then 2 bits

Prop and the Blackhole Midget is one I found on ebay


Prop and the Blackhole Midget

I want one of those Dave. And the workshop big enough to take it.

Prop, it's snake oil, it's a con. Don't you think so? If it was that simple there would never have been a rust problem on any car.

Cathodic Protection (CP), (read about the principle) can work on ships, bridges, and underground structures etc, but not on cars. You'd need an external circuit to make it work, and that would mean you couldn't drive the car. -- Parked in sea water or a lake for example. lol.

Zinc plating works, but that's a big job. So I think I'll just stick to simple resin and paint type solutions. :).
Lawrence Slater

could you supply more voltage to it say 36 volt and turn the rust back into metal......??? hehe
J D Craddock

Or 240V, and you might even make gold lol.
Lawrence Slater

I would suggest you can treat all the rust prone areas you list with good old waxoll - I think it would be ptretty easy to spray into the cracks and crevasses - I treated an old mini after a rebuild and it protected it very well for many years after... probably weigh a little less than seam sealer method you describe Guy? not that it would matter much ...
John Barber

going back to dave's coment of 25th may...
"Curiously, the MGB has a drip rail at the back of the rear wheelarch"

the midget also already has a 'drip rail' here as you can just about make out at the bottom of this pic...

graeme jackson

This thread was discussed between 25/05/2013 and 05/06/2013

MG Midget and Sprite Technical index

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