punto floor pan repair

[pondy]

i no there was rust spots coming through on my floor pan and have planned to wire brush it down and waxoyl it next saturday. put it up on the ramp today just to have a better look on how bad it is, its worse than i expected, has one hole and some other areas were the rusts needs cutting out and plates welded in.

in the floor pan there arte a few half moon cuts out, if you bend them back there is a rubber bung that when removed goes all the way to the carpet inside, every one of these has bad rust, see pic

at the rear of the car only there are to parts that look like jacking points but are no were near strong enough and just crush in, these look to be held on with a few spot welds and its rusted bad between to two metals. on side is rusted, the other is worse and has a hole.

the half moon cut outs with the rubber grommet i plan to cut out and weld a plate in, these seem totally pointless being there and just cause me trouble.

the jacking points at the rear im not sure on, i never use them, if im working at home i use the sill, the front subframe or the rear axle depending on what im doing, or take it to work on a ramp.
as its rusting all the way around the area i doubt you will get rid of the rust without cutting it out and replacing the part which i have been unable to find. can i cut there part out and weld a plate in its place? its not being used and is not a structual part as its held on with spot welds

what thickness material is best to use? i have a sheet of 1mm that should be enough to finish the job, or i have a sheet of 1.5 that may finish the job at a push.

i have never used waxoyl before, does it go dry or does it stay tacky?

i have never carried out any welding on a car, do i just have to remove the battery when welding?

planning to cut the rusted area out and weld from the inside of the car. what technique do i need? from watching alot of tv i noticed when welding pannels you do alot of small welds to stop the metal distorting, do i do this or just weld as normal. never welded upside down do that parts going to be a learning curve

 

[jaykay]

the holes with bungs in are very likely drain holes.car are dip primed at factory.
try to weld as much as you can from above,as welding from below is hard and painfull.
you can burn yourself alot.
try to measure thinkness of floor and use the same gauge if you can.

 

[pondy]

tonight i have removed the complete interior of the car do i can weld it all up. found out they are not rubber grommets, its the black sound proofing. there are 8 half moons cut into the lower channels of the floor pan, i think to drain any water out if it was to get inside. every one has rusted and will need cutting out, you can see were the water was trapped under the sound proofing.

11 holes in total, going to be a busy week. im 90% sure im going to remove the jack points. can confirm there are held in place by 4 spot welds and has rusted all the way around were the water has got between the joint and rusted, also not strong enough to jack on

 

[LewisT]

when welding from above make sure there are no fuel pipes underneath mate of mine set a car alight doing that.

 

[kelsham]

Hi, it is a good idea to disconnect the battery and the alternator before beginning repairs. Have a look at the tutorials on this site, they are excellent.

Regards Kels.

 

[bigbadbugga]

I've just done the same job on a Marea, the floorpan is only 0.8mm and very fragile, I struggled to weld it with my portamig 185 on minimum (coarse1-fine1-wirespeed2).

Fiats are awful cars to weld on. Make sure everything is pristine Clean and use the pulse welding technique.

Good luck.

 

[pondy]

.8mm isnt very thick for a floor pan, i got a large sheet to make the plates today, its 1.2mm so will be better than the material thats used! not got a chance to start on the holes yet, been busy on the outer body, all the bumpers are off and rust removed from the front and rear crash bars and these has now be waxoyl'd

the front and rear arches have been attached with a wire brush attachment on an angle grinder, some spots of rust on one front arch and both rears had rust setting in on the bottom edge of the inner liner, sils have also been wire bushed and these will all get waxoyl'd tomorrow, bumpers back on tuesday then the holes will be started wednesday. i would post pics in the project section but all it would be is rust, rust removed then covered in black wax

word of warning to anyone who has never used waxoyl, its nasty stuff and gets everywere, wear overalls, a hat, mask etc, not shorts and tee shirt like this dougnut

 

[bigbadbugga]

if you are using 1.2mm to repair you might have problems with the 0.8mm floorpan burning back.

 

[pondy]

what about if i weld it in short busts so the heat does not build up to much to blast holes?

 

[bigbadbugga]

You might need to weld slightly more on the thicker material, the problem with welding on different thicknesses is that to get good penetration on the thicker steel you need a power setting that is too much for the thinner steel.

Start your welds on the thicker sheet and feather onto the thin, and yes, the pulse welding technique will probably be best.

Practice off the car first with the same thicknesses you will be using.

 

[octo0072000]

water

tonight i have removed the complete interior of the car do i can weld it all up. found out they are not rubber grommets, its the black sound proofing. there are 8 half moons cut into the lower channels of the floor pan, i think to drain any water out if it was to get inside. every one has rusted and will need cutting out, you can see were the water was trapped under the sound proofing.

11 holes in total, going to be a busy week. im 90% sure im going to remove the jack points. can confirm there are held in place by 4 spot welds and has rusted all the way around were the water has got between the joint and rusted, also not strong enough to jack on

Just remember when you weld all the holes up

1/ the water cant now get out now because water must have got in to have rotted the floor out in the first place

2/ a 1 inch hole becomes a 6 in hole by the time you have cleaned it all up and cut out the rot especially under the jacking points
when you have welded it all up don't put the carpets back till after it's been out in the rain a few times so you can find the leaks
have fun

 

[pondy]

the think the water got in from under the car through drain holes in the floor, dont see how it got under the sound proofing, was stuck down well and took hours to get off, the water was only around the drain holes and no were else

i did think of that so i went out and got a larger sheet to do the repair

whats the deal with waxoyl, does it go hard or stay tacky? was a hot day today and its melted and dripped all over the floor, may take it off and try undersealer

 

[octo0072000]

wax on wax off ?????

the think the water got in from under the car through drain holes in the floor, dont see how it got under the sound proofing, was stuck down well and took hours to get off, the water was only around the drain holes and no were else

i did think of that so i went out and got a larger sheet to do the repair

whats the deal with waxoyl, does it go hard or stay tacky? was a hot day today and its melted and dripped all over the floor, may take it off and try undersealer

waxoil stays semi hard on a hot day runny it will harden off in a few weeks better than underseal because it's semi hard it's supposed to heal it self when it gets chipped etc

 

[pondy]

the end goal is get all the rust off and have the best protection on the underside and any areas that road salt and dit gets to. may be going a little over the top, only a 8 year old 1.2 fiat but it does 60mpg and runs great which is perfect for the price of fuel these days.
so waxoyl and leave it to dry or undersealer? what about on the sills? i wont be able to wash the car for a while?

tonight i managed to weld to holes and get another large patch cut out, its take alot longer than i expected.
welding it is showing to be a right pain, only a beginner and to be honest, i feel in way over my head but going to take it one hole at a time. clarke 150 in on min power and wire speed 3 and its blowing holes because the material is thin. i have been using short bursts in a side to side motion, am doing on side to the other, leaving it for a second to cool then carrying on, im getting penitration show on the underside, i have also done this on the underside just to make it stronger. welds look rough but its sealed all the way around, the more holes and practice i do the better they will get

thanks for all the help so far, i need it! glad there are people out there that can help

 

[octo0072000]

stone chip the sills you can get from car shops in spray cans or if you have a compresser in the shultz guns or under seal dont normally waxoil sills only waxoil in the inside cavity

 

[pondy]

stone chip just for the sills or the aches aswell? and waxoyl the underside?

was planning on using hammerite on the inner foot wells were i have welded?

have waxoyls the crash bars behind the bumper but not sure if i should have or not, just hope it gets dry

 

[octo0072000]

stone chip

you can stone chip the archs as well but it's not cheap just waxoil once a year

 

[pondy]

got 3 litres of 3m undersealer to do the arches and sills, inside were i welded and spare wheel well. i could have waxoyled the arches but would have been messy installing the bumpers and arch linners again

 

[pondy]

will have to get some pictrures of my welding up, the welding on the inside is good for me. the weld on the underside looks alot messier, im welding upside down (which ive not done before), car is jacked up so i can just get under it and its outside and windy. i get penertration come through and the whole joint is covered in weld so im sure its going to be strong enough, some i may have to grind down and go over