A problem

[nigel_bytes]

First of all Hi to everyone , I've been reading the forums for sometime and this is my first post so here goes.
I'm not a qualified welder just a simple hobby guy.
My MR2 T Bar H reg (1990) had a few bubbles on the Tbar roof so i decided to see just how things were, Well i was quite suprised to see this much rust after scraping all the paint off, Please take a look and help me out here, How would you go about repairing this ?
I have a clarke 110en fan cooled mig welder and a medium sized Argon-Co2 bottle. Comments please. Thanks

 

[rusty69bus]

cut where the green lines are repair rust then when piece back in

 

[nigel_bytes]

Sorry i should have explained a little bit more, That black cross-member is bolted on underneath, Another picture angle here showing a little more,

 

[peterd51]

Hi,

I'd clean up the metal as far as the end of the rusty bit to see how far it goes. If I couldn't get a repair panel (unlikely) then I'd try to find the same car in the scrap-yard and cut a piece out of that.

Then I'd remove the cross-member, cut out all of the rusty metal, trim the patch panel to suit and butt weld it in.

If you don't fancy cutting up old cars then cut out all the rusty metal and make up some new bits of steel to suit. It looks like it'll extend into the main roof judging by the blobby paint, so you may need two or three pieces to fully cover all the rot.

It's not going to be a quick fix I'd say.

Regards
Peter

 

[weldingscotty803]

take the cross member off. clen all the paint off until you get back to nice rust and bubble free metal around the repair. take all precautions with interior, take seats carpets out or cover them with something. cut back to decent metal. try and get it out as 1 piece. now make up the repair panel. copy the cutout by hammering flat ant using it as a rough template. make it oversized as you can always cut a bit off but it will take longer to add a bit. then bend it and try it for /size. tack into place. stand back. see if its ok. check for fire in the interior. tack in all corners then a tack every 1 inch. making sure the pieces to be welded are level. now stitch weld the repair. weld between two of the tacks, then miss two full gaps. if you dont you will concentrate too much heat in one place. when its all done get a 40 or 60 grade flap wheel and grind welds flush. prep surface for filler using meths or some kind of cleaner that evaporates. mix filler anf fill to your hearts content . sand after half an hour. add more filler if required. re sand. prime. i always put a few coats of primer and use some 240 wet and dry to prep the surface for car colour. when adding car colour apply very light coats. i had to apply 11 coats all together to get a decent match on a toyota land cruiser the other day. remember to mask round where you dont want the paint. then tcut after about 6 hours
good luck

atb scott

 

[nigel_bytes]

Thanks for the replies folks, This afternoon i removed the black bar going across (4bolts) Cleaned up a little and the cut out a small section, Will try and cut up a piece of an old wing tomorrow and shape it, The flat section (towards the windscreen is pitted) but not rusted through not sure how to handle this bit, I dont want to take out the windsceen so i will have to use a rag and cold water to keep it cool when welding, Can i get away with filling the pitted section ?, Thanks again everyone

 

[Robotstar5]

The flat section (towards the windscreen is pitted) but not rusted through not sure how to handle this bit, I dont want to take out the windsceen so i will have to use a rag and cold water to keep it cool when welding,

Make sure the windscreen is covered when grinding or welding, the sparks will stick to the glass.

 

[malcolm]

Looks like a proper repair in progress. I was going to suggest primer and seam sealer.

The pitted metal can be filled and should last OK so long as it's cleaned up reasonably well before filling. If it's thin you might want to extend the hole to a point where it's a little less thin to make it easier to weld to. How comfortable are you with butt welds at that thickness? Well worth getting the repair section to fit very accurately without gaps (make a template from a cereal packet first) and setting the welder up on scrap before tackling it. If you do get stuck we've got a thin metal technique that might be helpful.

Shouldn't be any need to cool the windscreen, but it will need covering.

 

[peterd51]

Hi,

before filling in the pitted roof I'd give it a coat of Kurust or similar to kill off the rust.

Regards
Peter

 

[Rusty]

As Malcolm said make a template from cardboard it easy to get the exact shape , rust treat everything that shows any rust , when you weld your plate in make sure the new plate does not stand ' proud ' of the original you can then get the perfect shape with a skim of filler.Also consider removing the seats and carpet it's an easy job and have someone on fire watch in the car with a squirty bottle of water ! ( always pays to have a proper extinguisher at hand just in case ).

got beat to it ..LOL.