73 MGB GT restoration

[Ian F]

Hi Harry,
just a brief reply this time:

# I have two blocks, one that just fits in the palm (hard rubber) and a larger one which is about 8" x 4" from memory (don't have it in front of me to measure it). This one is sized to take the standard wet and dry sheets when folded and torn to size. I could really have done with a longer one as well to use on the larger flatter areas to avoid putting waves/ripples into the finish. For the very curved areas like the tops of the wings I use my hand with no block, making sure to sand in long even strokes with the wet and dry curved around the shape of the panel.

# not such good news about the sill! I would guess that if the outer sill has not been repaired properly you may well find that you need to do the diaphragm sill, castle section and possibly the inner sill as well. This will mean removing both wings, and quite a bit of welding. All very straightforward but will take you some time and need some care. I did both sides on my BGT and put 5 panels on each side including the jacking point.

That's about it for now!

Best of luck with it,

IanF

[Hazza1190]

Hi Ian,

What was the larger sanding block made out of? I cant see any that are longer than about 5/6 inches? Can you remember where you know where you got your one from?

Yeah its a bit of a shame, but it will be some good experience nevertheless! That was the main reason behind this car really, i wanted to push myself a little bit as it will be my first restoration! Did you use the steelcraft kit or a heritage kit?

Kind Regards,
Harry.

[Ian F]

Hi Harry. You need to find your local motor factor or autopaint supplier! They will undoubtedly have a range of sanding blocks/flatbed Sanders for use in vehicle body shops. Mine has no name on it but is plastic with metal clips at either end to hold the paper.
I bought my panels just as required as I went along, and got them from Moss.
Ideally you should get your equipment and consumables from a professional body shop supplier, including the wet and dry paper. The quality of the stuff you use really will make all the difference to the ease of use and the quality of the finish.

IanF

[Ian F]

Bosch 2608601218 Hand Sanding Block Set, Black, 160 x 85 mm

Harry - this Bosch item is very similar to the larger one I have, available from Amazon.

Frost automotive do several sets of long bed Sanders etc. but I always find their prices a bit steep!

IanF

[Donie]

Hello MGB'ers.

I've read, with great interest, the great nuggets of information in this thread on painting, and preparing.

Firstly, my roadster is a very hard to love, 1978 RB, in the equally hard to like Hunter Green, BRG.
I have owned chrome bumper roadster and GT back in the day, when the cars were much better in many areas, apart from the bumpers.

The green, in my opinion, does very little for the lines of the car, either roadster or GT.

I intend to change the colour, but since I don't expect to be able to make a silk purse out of a sow's ear, I don't intend to worry about the engine bay, since the work involved there is tremendous.

First question relates to crustiness in the region of the seam beads on the tops of the rear wings.

There is a lot of underlying rust, and the passenger side seam bead will need to be replaced almost in it's entirety.

On that note is it necessary to replace the seam entirely, or can you be successful in covering a join if you don't do it all?

Secondly, what is the long term prospects of rust pitted areas where you use rust converter?

So far I've used Loctite SF 7503. I tried to source the much aclaimed Ospho, with not success. Apparently they don't export to Europe, or the U.K. I've also got Hammerite Kurust, although I've not used it yet.

The pitted areas, cleaned back to the steel, have responded well, and turned to the expected black colour.

What next, and how long could you expect to keep the rust at bay?

[Bumpa]

I don't want to pour cold water on your hopes but those seams are a poor design fault and are very prone to rust. The fillet that covers the seam is a steel T-section, so you have three pieces of steel welded together - a recipe for rust as you can't weld through paint, so inside the joint is bare metal. It's only the outer paint that seals it as the cars came from the factory.

Once the rust has started it is nigh on impossible to cure it without major dismantling. You can sand it back and put on so-called rust preventative solutions, but in my opinion, after 50+ years of trying very many types, they are not a complete answer and the corrosion will always come back. When my GT was rebuilt I bolted the two panels that make up the rear wing seams and didn't use the filler strip, making good with body filler. It looks good and has lasted 12 years so far with no sign of rust. At the front I thought having removable front wings was a good idea, so I did it the conventional way with as little welding as possible. The corrosion has come back.

Sorry. It's a mystery to me why MG didn't use plastic seam strips as on the MGA and Morris Minor, with the two panels bolted through. No welding, no rust.

[Ian F]

My solution, about 12 years ago, was to fill the joint with brazing and then add the top strip afterwards. Underneath the seam I coated it with Dinitrol wax.
No signs of rust to date!!

Ian F

[Donie]

Hello Ian,

After you filled the seam with brass, how did you fix on the top strip?

Did you use the original T section type, with the vertical section cut off, or a substitute strip?

I've hear of someone using the stick-on lead strip, used for pseudo leaded lights glazing. Would this be durable enough when primed and painted?

I've also got some small holes in the ledge of the driver's side front wing, near the door jam, just over the chrome strip position.

It doesn't really call for tearing off the wing,

[Ian F]

Original T section strip with the bottom removed. Brazed into place. Then followed by much fine grinding, filing and filling to get it looking as good as possible. I use Plastic Padding Professional as a filler - it has some flexibility. Must be applied to bare metal not sandwiched between paint layers.

Ian F