Floor pan Holley Rust

[ale36]

Evening all I just finished removing the seat out of my tigra a as I'm fitting new bucket seat and lifted the carpet up after feeling and hearing the floor underneath me crunch and I was greeted by this
Now the question is. Will it be better to cut it out (some one outline how much) and weld a new piece in or just weld a new plate over it? I would prefer to take it out and weld a new patch in rather than leaving it and welding over it. What's everyone's opinion?

 

[CompoSimmonite]

I'd remove all the carpet including under dash / wheel arches and check carefully to see if there are other areas that will need attention at the same time.

Paul H

 

[steveo3002]

wont be a great deal more work to cut a neat square and drop a piece in

would depend on the car for me , if its a rough old shed that needs to last another year then patch over it , if its tidy then do it right

 

[ale36]

I'd remove all the carpet including under dash / wheel arches and check carefully to see if there are other areas that will need attention at the same time.

Paul H

I done that lat night on the driver side it's just that patch. Just need to do the passenger side fingers crossed.

 

[ale36]

wont be a great deal more work to cut a neat square and drop a piece in

would depend on the car for me , if its a rough old shed that needs to last another year then patch over it , if its tidy then do it right

It's a tidy job Steve so I will cut out a square and put a new piece in. Can any one recommend what gauge steel sheet I should use and how much I need to remove?

 

[octo0072000]

I'd remove all the carpet including under dash / wheel arches and check carefully to see if there are other areas that will need attention at the same time.

Paul H

take the sill covers off to see if the inners sills are ok

 

[steveo3002]

id imagine its something like 1.2mm, prob had one of them bungs in it originaly

 

[CompoSimmonite]

I'd be tempted to find a sound car in scrapyard and cut a repair panel out of that together with the bung.

Paul H

 

[Coo]

Cut out and patch it,
it's rusted at that drain hole,
at least there's that reason for it going there...

 

[ale36]

would i need the drain Hole? after all they seem a bit pointless as they have a bung in

 

[Wallace]

I would start looking into where the water came from to cause the rust in the first place. Was the bung still in place when you pulled the carpet back?

 

[CompoSimmonite]

would i need the drain Hole? after all they seem a bit pointless as they have a bung in

The drain hole will be needed during the manufacturing process. They drip the whole body into a massive vat of primer or whatever. So not needed but on the other hand why had the original rotted away - because you have a water leak (maybe past door seal ?). This leak therefore needs sorting before you repair the rot otherwise it'll rust out again plus carpets will be soaking. At least the rot hole allowed the water to drain away !

Paul H

 

[Wallace]

Great minds think alike eh Paul? Those holes are also used to align panels on the chassis jigs and are used as measurement datums.

 

[ale36]

Thanks for the replys I just though they where drain hole for when people drove into floods. The water came in about 3 months ago when I left the car outside with no bonnet, no engine and no heater blower. I have made some progress comment and criticism welcome tell me what you think

 

[Wallace]

Can I presume you have trebled the size of that hole chasing rust beneath the undersea on the outsidel?

 

[BrokenBiker]

even if you do happen upon a flood that you have to go through and water gets in, it only takes a few second to whack a 10mm hole in the lowest point and drain the water. wont take long to fill the hole back in either, or to make a new bung to fit it.

just drying the carpets that a pain

 

[ale36]

Can I presume you have trebled the size of that hole chasing rust beneath the undersea on the outsidel?

Errrr actually no I didn't. The rust pretty much stopped at the size of the hole. I decided to cut it out a lot more due to the chassis being right underneath the edge of the hole hard to explain but if you look at the picture you'll see what I mean

 

[Pigeon_Droppings]

I'm a beginner so take everything I say in context. You may need to do the repair in two pieces as it looks like you've cut out part of the angled profile towards the bottom of your last picture...unless you are good at bending steel? Shame the right hand edge of the hole has gone into the turret on the right hand side...hard to see how much of the floor is left to weld to on that right side...you might have to make a call on how you want to fix that bit as the floor looks like it's sandwiched between that top piece and maybe some structure underneath?

 

[ale36]

I'm a beginner so take everything I say in context. You may need to do the repair in two pieces as it looks like you've cut out part of the angled profile towards the bottom of your last picture...unless you are good at bending steel? Shame the right hand edge of the hole has gone into the turret on the right hand side...hard to see how much of the floor is left to weld to on that right side...you might have to make a call on how you want to fix that bit as the floor looks like it's sandwiched between that top piece and maybe some structure underneath?

I'm a beginner too but did do welding at college, i should be able to weld a replacement patch in one piece as the bend in not complex should be able to get the shape by just clamping it in a vice with a length of wood to fold it on to, as for the welding again when i cut the hole i left just enough to the right so i could get a weld on it, there is no structure underneath apart from what you see on the picture i have highlighted the weld path that i have planed but if any one feels i should do it differently please let me know

 

[mike 109444]

Ale Before you start cutting you nice new piece of steel, get your self a sheet of stiff cardboard (cereal pack) and cut a piece aprox 1/2" bigger all round. Then slip the cardboard from under the car onto the chassis piece in the middle of your pic. Now draw round the hole onto your card. Also mark round the chassis in middle (from underneath). Then remove cardboard, cut to size and use as a template for marking up your new metal. also using a center punch mark where the chassis is. Allow a small amount of over size when cutting out your metal. Remeber you can always cut it smaller but you cant cut it BIGGER!! Using the marks from the chassis mark in aprox 3/8" and drill holes every 1 to 2 inches for plug welds. You only have 2 shown on your markup of where you are going to weld.
If you use a jack and a piece of wood you should be able to slid your new metal in like you did with the cardboard, then using jack with wood to spread the pressure jack the new metal into position (don't over do it cos you will push car off axle stands!!!) Now tack ever 2 to 3 inches all way round. then fill in between tacks a bit at a time (avoid heat build up) If you place a lamp under car, you should be able to see any missed bits from the light shining through. Once done using a heavy weight(or push with a screw driver) placed on top of area where the chassis is you can now do the plug welds. If you don't push down you will end up with a gap that water will build up in to then rot out.