11BL rusty floor

I made some pretty good progress today. I used the "grind and peel" method to reveal where the original plug welds held the inner sill to the center sill. You can see the remains of the plug welds here.
200919 sill repair (1).jpg


Then I used the MIG welder to plug weld the patch panel to the center sill and put down a few tacks along the upper edge.
200919 sill repair (6).jpg
Lots more welding but I feel like I am over the hump on the sill repair.
 
citroenthusiast said:
I made some pretty good progress today. I used the "grind and peel" method to reveal where the original plug welds held the inner sill to the center sill. You can see the remains of the plug welds here.View attachment 125660

Then I used the MIG welder to plug weld the patch panel to the center sill and put down a few tacks along the upper edge.
View attachment 125662 Lots more welding but I feel like I am over the hump on the sill repair.
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Nice, not only that, you now know the inner sill is good too. How would you know unless you cut a big hole!
 
Made some decent progress this weekend. The sill repair is complete and the aftermarket floor panel has been trimmed so it will drop in place.

200927 floor repair (9).jpg




The idea I had for splicing the floor panel into the old floor was to make a scarf cut in the V-shaped reinforcement along a 45 degree angle. I then made a reverse scarf cut in the V-shaped reinforcement in the car. The idea was so the floor would be supported with the weld somewhat in compression, rather than pure shear.
200927 floor repair (5).jpg
 
What sort of welder are you using? (I need a welder that'll work that well on thin metal!) That is an incredible weld given it appears to be through paint! If I'd tried that with my welder if would be spattering everywhere and pinholed from the paint burning off in the weld.

seeya
Shane L.
 
DoubleChevron said:
What sort of welder are you using? (I need a welder that'll work that well on thin metal!) That is an incredible weld given it appears to be through paint! If I'd tried that with my welder if would be spattering everywhere and pinholed from the paint burning off in the weld.

seeya
Shane L.
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Weld through primer ?
 
robmac said:
Weld through primer ?
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I've only ever tried weld through primer one time.... It made a huge mess and caused holes to burn through on thin metal ( I'm betting the stuff I bought was no good ... and I need to try something different :) ).
 
DoubleChevron said:
I've only ever tried weld through primer one time.... It made a huge mess and caused holes to burn through on thin metal ( I'm betting the stuff I bought was no good ... and I need to try something different :) ).
Click to expand...
Upol make an aerosol can weld through primer.

The sheet needs to be free of rust before you apply.

Generally MIG welding needs clean sheets, either new or cleaned with a rotary wire brush or angle grinder with abrasive disk.

Both parts of the welded joint need to be in reliable contact with the earth electrode.

Then it's a case of setting the ideal current and wire feed rate with sufficient flow of shielding gas.
 
robmac said:
Upol make an aerosol can weld through primer.

The sheet needs to be free of rust before you apply.

Generally MIG welding needs clean sheets, either new or cleaned with a rotary wire brush or angle grinder with abrasive disk.

Both parts of the welded joint need to be in reliable contact with the earth electrode.

Then it's a case of setting the ideal current and wire feed rate with sufficient flow of shielding gas.
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That bit I get :) In my case the weld through primer was hard to initially strike and arc through .... then splattered a lot and caused metal burn through very easily. I haven't tried it since :)
 
DoubleChevron said:
That bit I get :) In my case the weld through primer was hard to initially strike and arc through .... then splattered a lot and caused metal burn through very easily. I haven't tried it since :)
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Difficult to strike can be a poor earth. What is you welder type ?
 
robmac said:
Difficult to strike can be a poor earth. What is you welder type ?
Click to expand...
It because I needed to scratch through the primer a bit before you could get the arc started. I'm thinking it was just a very poor quality weld through primer I had :)
 
DoubleChevron said:
What sort of welder are you using? (I need a welder that'll work that well on thin metal!) That is an incredible weld given it appears to be through paint! If I'd tried that with my welder if would be spattering everywhere and pinholed from the paint burning off in the weld.

seeya
Shane L.
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I wish I could take credit for those welds, but they are part of the reproduction floor. My welding is the mess visible in the far end of the other photo.... The floor metal isn't terribly thin. I would say the sheet is about 18 gauge and the V shaped reinforcement even heavier. I have been using the MIG welder on the 18 gauge patch for the sill. I used TIG for the 24 gauge box supporting the seats. It is always a challenge welding to rusty metal since the thickness varies with the level of deterioration. Brand-new metal is pretty easy. The coating on the floor panel seems to be tougher than paint. Maybe some sort of plating??
 
Used weld-through primer everywhere on my TA "Camweld" is the brand -in aerosol cans - seems to work OK
Regards, Rob
 
More progress. The floor is welded in place. Turns out with this relatively heavy steel the MIG welder worked the best.
201015 progress (8).jpg
I I still need to grind the welds down and I will probably at least double up on the number of welds, but what an improvement over where I started. Witness marks on the top surface show I at least I am getting decent penetration with the welds.
201015 progress (7).jpg
a
 
That is really nice looking work. A fabulous job of welding "upside down" for sure :dance: Do the repro floorpans have the stiffeners welded on in the wrong spot? They don't line up with the back floor!
 
DoubleChevron said:
That is really nice looking work. A fabulous job of welding "upside down" for sure :dance: Do the repro floorpans have the stiffeners welded on in the wrong spot? They don't line up with the back floor!
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Yes. The V shaped reinforcements on the reproduction floor did not line up. It actually makes it easier to install the floor since you can leave some overlap between the original reinforcements and the new floor. The repair will definitely be noticeable from underneath, but structurally it will be sound.
 
Can you remove and realign the V stiffeners? After all they are needed to house and protect the brake line and fuel line! Should not be too difficult to do and would look so much better!
 
It would be very difficult to move the stiffeners because I would have to grind away all of the welds (without damaging anything else) then re-weld everything. Instead of completely refabricating the floor panel, I will make a transition to accommodate the brake and fuel lines, or I will fabricate a secondary shield. My concerns were, in descending order; (1) structural integrity; (2) environmental integrity; (3) appearance from inside the cabin; (4) appearance from underneath. Priority #4 lost out.
 
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