Bodywork: Floorpan Welding, Rear seat footwells Options

[GialloEvo94]

Well I manged to start and complete my floorpan welding this weekend Note that I'm a complete novice welder with no previous experience of welding on a car and the only welding I had done prior to this was a couple of practice sessions with some sheets of metal on a work bench. I was actually getting some quite nice welds on the bench but unfortunately they didn't come out quite as neat on the car due to the limited space to work in and needing to be a contortionist to get some of the angles with the torch in my right hand The welds themselves are a little taller than I would have liked them to be and a bit wiggly in places but there is good penetration and the welds are very strong with no gaps so I'm satisfied that the job is a good'un and no-one will see them under the carpet anyway The drain holes I left in place have been fully treated and sealed up so they won't cause any problems in the future. At least the MOT man will be happy come June

Tools Required

• MIG Welder (gas capable with the ability to go down to 30 amps)
• 0.6mm Steel MIG Wire
• 0.6mm MIG Welder Tips
• Argon/CO2/O2 Gas Mix (95% Argon, 3% CO2, 2% O2)
• Argon Single Stage Regulator
• Welding Mask (auto-darkening type recommended)
• Welding Gauntlets (long gloves)
• Angle Grinder with 1mm Cutting Discs
• Electric Drill
• Various Rotary Wire Brushes (for drill and/or angle grinder attachment)
• Various Files
• Small Ball Pane Hammer

Parts/Consumables Required

• 0.8mm Mild Steel Sheet
• Thin Cardboard Sheet (used to create templates for cutting the correct size metal patches)
• Chemical Rust Treatment (i.e. Hammerite Krust)
• Zinc Paint (i.e. Davids Isopon Zinc 182)
• Hammerite Paint (Smoothrite)
• Seam Sealer (i.e. Tiger Seal)
• Underseal

Below is a rough guide showing what steps I took to do the job...

1. Seats and trim removed, carpet pulled back and black tar sound deadening patches removed (took me nearly 2.5 hours to chip those nasty things away from the floorpan )
   
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2. Cables wrapped in wet rags and tied up out of the way to protect them from spinning wire brushes/discs and any sparks/heat, then the paint stripped back to bare metal on and around the corroded areas using a wire brush in an angle grinder and another one in a drill.
   
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3. Rust removal treatment (Hammerite Krust) applied to the drain holes that were still intact.
   
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4. Sections containing irreparable drain holes cut out using a 115mm x 1mm cutting disc in an angle grinder.
   
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5. Cardboard sheet was used to make templates that fitted the cut-out holes and the templates were then used to create the correct sized metal repair patches. These were cut out of 0.8mm mild steel sheet then tacked down over the holes before being hammered into the corrugated sections of the existing floor pan with the ball part of a ball pane hammer. They were then finally seam welded over the holes using a Clarke 160EN MIG welder set at 30 amps with 0.6mm solid wire and an Argon/CO2/O2 gas mix (95%/3%/2%) set at a flow rate of 10 litres per minute. The resulting welds were then cleaned up with a rotary brush in preparation for painting.
   
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6. Zinc paint applied (Davids Isopon Zinc 182) to protect the new metal, welds and the other treated drain holes.
   
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7. Polyurethane seam sealer (Tiger Seal) smeared around the seams, welds and drain holes for further protection (and to seal up the drain holes completely to prevent any more moisture getting in through them and causing this problem again).
   
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8. Hammerite smooth top coat applied on the top and bottom for another layer of protection
   
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9. Underbody seal applied on the bottom (Hammerite Underbody Seal with added Waxoyl) as a final layer of protection from road debris and the elements.
   
   (Sorry, no pictures of this because I was more interested in just finishing the job so I forgot to take any snaps )
   
   
   
10. Finally carpet, trim and seats all replaced to complete the job

[Francophile69]

congrats..looks like a good job, you must be well chuffed!

got mine to do soon...

[NaanBread]

very smart welding for a beginner! one day I will be as good as that

[neilandbob]

Looks good GE, the MOT man can't argue with that. I wouldn't worry about how the welds look, it's not absolutely critical with them being under the carpet, it'll just be your little secret! I never thought to say but i've found that welding with my left hand, (i'm right handed), is not as tricky as, for example, using a screwdriver or cleaning your teeth. Give it a shot on the bench, as you've found there will be occasions when it will be useful.

[xyy81t]

damn it GE! you said you wouldn't put photo's up! good job, i wish mine only needed that amount of work. i finished my welding this weekend too but unfortunatly good old Zoe has eaten me i the process, my back is absolutely caning and to make it worse i have to bike to work tomorrow!

looks like you've been conservatie with the old tiger seal compared to my effort but then your welds are tidier so i guess less is needed to cover them up

[930Tech]

I think someone like veng have missed a real sales opportunity here.

Rear floor pan sections for tipo based cars would have sold like hot cakes, probably still would.

I hate my welded floor and would much sooner have a section welded in with the shape of the original floor pan.

[Macca]

good work!

[GialloEvo94]

congrats..looks like a good job, you must be well chuffed!

I think relieved is the word I have to drive down to Gatwick in it on Wednesday so I had to get it finished by the end of this weekend no matter what which meant I was battling against time. I got the final bit of interior fitted at 8pm (in the dark) so only just made it. It actually went a lot better than I expected it to and the good weather also played a big part in that

[GialloEvo94]

damn it GE! you said you wouldn't put photo's up! good job, i wish mine only needed that amount of work. i finished my welding this weekend too but unfortunatly good old Zoe has eaten me i the process, my back is absolutely caning and to make it worse i have to bike to work tomorrow!

Well I originally thought there was a good chance that my novice welding might turn out to be a complete embarrassment with holes burned everywhere but thankfully I managed to do something half decent I think I have just been lucky with mine and caught it in time before things got any worse. All the drain holes did have some corrosion around them so it would only have been a matter of time if I hadn't treated the other ones properly and sealed them up. The drain holes in the front footwells on mine look like they are also starting to go as they also have some corrosion around them but not enough to need cutting out and welding (yet). If I do something about it this summer then I should be able to get away with just wire brushing them back, treating them and then sealing them up like I did with the ones on the back that were salvageable.

My whole body is also aching from top to bottom with all the abnormal bending, twisting and scrabbling around under the car over the past two days (I must be getting old) and my hands are an absolute mess with cuts, grazes,and ingrained oil/dirt that I just cannot get off with either scrubbing or chemicals. I'm certainly looking forward to the next few of weekends without doing anything at all on the car

[langers]

Good work fella - Iv welded up eermmm.... 3 or 4 of these now!

[Hybrd]

Id say this could be used as a good guide for anyone wanting to tackle the job themselves so moved to how-to's

Nice work GE

[Tifosi1976]

Top work GE!

Well done sir!

[delta303]

bril guide , fantastic .

[Alfa-Si]

Just starting prepping my rear floor pan for welding.
Is there any tips for getting rid of that bloody tar stuff? Cause I think all I'm succeeding in doing is making a mess.

[GialloEvo94]

Is there any tips for getting rid of that bloody tar stuff? Cause I think all I'm succeeding in doing is making a mess.

A good flat-bladed screwdriver, a wooden mallet and a lot of patience! If you're lucky like some people are, it will chip off in larger chunks. Mine didn't and it ended up taking me a good 2-3 hours just to chip away the two in the rear footwells

[Alfa-Si]

A good flat-bladed screwdriver, a wooden mallet and a lot of patience! If you're lucky like some people are, it will chip off in larger chunks. Mine didn't and it ended up taking me a good 2-3 hours just to chip away the two in the rear footwells

Thanks for that, I'll give that a go tonight and hope I don't just put the screwdriver through the floor.

[Cloverleaf76]

Thanks for that, I'll give that a go tonight and hope I don't just put the screwdriver through the floor.

Don't worry about it: if it goes thru you need to replace that bit anyway

[chrisss-m]

The best method i found to remove the black tar type sound proofing, is to heat it with a heat gun and the scrape it away with a paint scraper.

It peels away in quite big peaces, just don't get it too hot or it starts to melt

hopeflly useful to someone:)