RD7 Radiator tank busted

Hi, Perkinsengineer.
Good welders can do some pretty remarkable things these days with modern technology and techniques. I don't claim to be a top quality welder but I'd have a shot at repairing that bottom tank, either with carefully selected scraps of cast iron welded together to patch the hole or by making up a piece of mild steel to the shape and welding that in. The problem with the mild steel approach might be different expansion rates but I'd 'havago'.

Some 'judicious preheating, peening and grinding' would be in order, whichever way was chosen.

The cast pieces would probably give the more 'authentic' finish.

Just my 0.02.

Just my 0.02.

Shane, it's all in the prep - that part can be fixed. Remove the bottom tank, clean it thoroughly including the rust around the wound, discuss with a welder experienced in cast steel welding that has the facilities and materials - including a sand tub to bury it in after welding to allow a slow cool down. It looks like you have the missing part lying on the ground. Don't hurry the repair - take the time and do it right and it will be as good as new

Jb weld

Ha ha

Regards

Take it to someone that can braze the broken piece back in. Core looks salvageable

Looks to be plenty of wall thickness to work with for a brazing repair. I would not attempt welding.

Although not done by me, or in my time, I have similar size patches on D8 radiator tanks which have been successfully brazed back together sometime in the past. They show no signs of failure many years on, so done correctly with the right technique, it can be done.

Thanks all for the replies, it seems like the general consensus is that this is fixable - most like by brazing. I will strip down the rad & take the tank to a local chap who I am told is handy with repairing castings. I will take the core to a local rad shop for testing, or maybe just wait until I get the bottom tank back and build it up & test myself. The fins are corroded into dust at the bottom so I will give it a good wash out first & see how bad it looks. niel - well spotted, a piece is on the ground, but not all of it - the repair would need another new piece of cast brazed in I think

Sounds good - let us know how the finished product turns out

if you have the bit that broke out or a suitable casting to raid for donor material (you can also cut a bit of mild steel plate to size and use that) brazing with mang bronze is the answer. dismantle, soak it in caustic soda or cleaning vinegar first to clean it and then heat in a oven you want it 250 degrees celcius or better keep heating it with a rosebud till it nice and hot say near 400 degrees. and braze it up. a second straight propane heating torch is good to keep the casting warm while you weld its just so it doesn't cool to quick or unevenly and stress crack.

then bury it in dry sand that has also been warmed easiest way is dig a big enough hole in the sand and light a fire in it. pine timber burns hot and fast. prep the hole as you braze the part so it ready to go and your not using a heap of gas to keep the part hot. let it cool a couple of days buried in the sand.

then coat with a epoxy such as devcon to seal it on the inside and prevent corrosion. glyptal would also work