Floor board replacement , how hard is it really ?

[Dakar Timm]

About a year and a half ago I noticed a soft spot in the drivers side floorboard about 8" in front of the seat.
I pulled the mat and carpet back to see a fairly small hole ,maybe 2" in diameter .
I talked to a few body shops about having them replace the piece with a replacement from AMD .
After waiting for far too long for an answer ,I'm wondering just how hard it can be .
I've been welding for years as part of my occupation .
I'm more concerned with screwing it up in front of my wife than anything.
Do I cut out the bad part to the exact sixe of the replacement panel ?
How does on keep the thin panels tight and level with each other when I can't use clamps ?
When I'm done , do I use a heat gun to get the old rust proofing off the bottom ?
Thanks

 

[6PKRTSE]

Just take your time, mark, measure several times.

 

[Belvedere408]

I just replaced a 3x3 hole under my gas pedal in my 67. I went with 20 gauge, keep your gap small. I used a magnet to keep it together since can’t use clamps.

 

[icetech]

Take your time... if you think the hole is 2" cut out 3-4.... i just went through this and trying to save metal made it worse as you are trying to save metal that is half **** and sucks to weld to.. if it's a small hole like thhat i wouldn't replace the whole floor but that's just me... just replace the bad spot.. Watch some fitzee vids he has great techniques for doing patches... made it sooo much easier.

 

[Durandal25]

About a year and a half ago I noticed a soft spot in the drivers side floorboard about 8" in front of the seat.
I pulled the mat and carpet back to see a fairly small hole ,maybe 2" in diameter .
I talked to a few body shops about having them replace the piece with a replacement from AMD .
After waiting for far too long for an answer ,I'm wondering just how hard it can be .
I've been welding for years as part of my occupation .
I'm more concerned with screwing it up in front of my wife than anything.
Do I cut out the bad part to the exact sixe of the replacement panel ?
How does on keep the thin panels tight and level with each other when I can't use clamps ?
When I'm done , do I use a heat gun to get the old rust proofing off the bottom ?
Thanks

I think you'd be far better off repairing it....unless there are pin holes radiating all over. Normally a 4 inch hole means 12.....get under the car with a light in the cabin....pull the carpet and looks for the pins. A full pan replacement is only advised if she is really rotten....you can get some sheet metal and fab a patch yourself for very little money, and not need the AMD panel at all.....in most cases, its better if you d...given the cost and extra fitment that always arises. I did repaired about half the panels it the 67 Coronet this way....and got better and better for each one I did......by the end....I went back and fixed the ones I started with. I'm sure you're quite skilled at metal fab, and will find this fun.

 

[Don Frelier]

You can also pull it together with pop rivets weld it and then go back drill out the rivets and weld the holes. Depends how fussy you are

 

[Matthew J]

Take your time... if you think the hole is 2" cut out 3-4.... i just went through this and trying to save metal made it worse as you are trying to save metal that is half **** and sucks to weld to.. if it's a small hole like thhat i wouldn't replace the whole floor but that's just me... just replace the bad spot.. Watch some fitzee vids he has great techniques for doing patches... made it sooo much easier.

+1 on the Fitzee videos. Informative and a hoot.

 

[BeepBeepRR]

I watch this guys videos very entertaining and he gets stuff done. Puddins Fab shop on YouTube.

 

[Dave6T4]

When we did my front floor, we used self-tapping screws instead of pop rivets to hold the panel down to crossmembers before welding them solidly. When done, we removed the screws and welded the holes.

 

[Paul_B]

I had a small hole on the drivers side floor that sounds similiar to what you have. I just welded in a small patch from some scrap metal I had and it looks good. You can see it from underneath if you look hard enough but mine isn’t a show queen you put mirrors under to display.

 

[RGAZ]

To answer your questions as best I can:

Do I cut out the bad part to the exact size of the replacement panel ?

Cut out the rusty parts and remove any rusty part that is spot welded to cross member, seat support, rocker, and firewall. I cut close to the area and then use a pnuematic gun to separate the spot welds (for parts you will not reuse). Fit your floor in and let it overlap the other steel. Screw together/down and then cut through both parts so you get a butt connection. Make sure you are cutting through good metal (not rusty). Remove panels, punch holes, grind off paint etc. and prep to weld. (warning! Be aware of other parts underneath like brake lines, fuel lines, parking cable, etc.)

How does on keep the thin panels tight and level with each other when I can't use clamps ?

If you cut through both, they will be close. I use a few strong magnets to hold them level, sometimes I will push the higher panel to make it level. Tack in place and then get to work welding in small dots. I clamp at the firewall in the wheel well and then screw in crossmember and seat supports.

When I'm done , do I use a heat gun to get the old rust proofing off the bottom ?

Remove any way you want, you had to clear some away for the welding anyway. The rest will burn and stink you out.

Hope that helps.

RGAZ

 

[icetech]

Watch this part of the vid.... see how he tacks the patch over the bad area, then uses a wheel to cut around the patch and weld it as he goes... that trick makes almost any patch beyond easy.. saved me soo much work doing my quarters... no need to make a perfect patch and worry about getting it even with the existing floor since you are cutting it in perfect as you go.

 

[Matthew J]

Watch this part of the vid.... see how he tacks the patch over the bad area, then uses a wheel to cut around the patch and weld it as he goes... that trick makes almost any patch beyond easy.. saved me soo much work doing my quarters... no need to make a perfect patch and worry about getting it even with the existing floor since you are cutting it in perfect as you go.

The cut-and-butt is a definite time saver. Amazing how he builds up complex panels in pieces using simple hand tools. Probably want to wear welding gloves and a face mask though... don't know how many years of experience you would need to skip those. Thick Irish accent optional.

 

[67charger383]

I used POR-15 on all the nasty surface rust parts of my floor pan and cut out and welded in patches where there were holes. Covered the welds in seam sealer. Worked ok for about $100 in material and having a solid floor to work with

 

[icetech]

The cut-and-butt is a definite time saver. Amazing how he builds up complex panels in pieces using simple hand tools. Probably want to wear welding gloves and a face mask though... don't know how many years of experience you would need to skip those. Thick Irish accent optional.

Yeah... i had places where i had to cut out and fit pieces ahead of time cause i could get behind to remove it doing it the other way and it took FOREVER...the cut and butt is soo good.. What annoys me bout fitzee is how when he grinds his metal clean it looks amazing.. mine looks like ****

 

[icetech]

I used POR-15 on all the nasty surface rust parts of my floor pan and cut out and welded in patches where there were holes. Covered the welds in seam sealer. Worked ok for about $100 in material and having a solid floor to work with

Same as i did in my car.. ended up doing 5 2"-5" patches and covering in brush on rustoleum and am ready for killmat now.. just finished last night

 

[blue69runner]

Remove the under coating with stiff putty knife and heat gun aimed at the putty knife end. Need a fan to move the fumes away from you. Then used a wire wheel on my die grinder to finish the clean-up. I used bed liner to recoat. In place of the under coating. Take your time if you don't have and overlap patch then remember to move around when welding the patch in so it won't warp on you. Do you have a mig welder? Best for the job.

 

[icetech]

I used a propane torch and putty knife.. i tried all the tricks people said like goo gone and stuff.. nothing works as fast as heat and scraping... then i wire wheel and use brush on black rustoleum... the stuff is like cement when it dries and won't separate from the metal and hold moisture like some rubber undercoats.

 

[gdrill]

Pull carpet back and cover it up to protect it.
Cut hole to clear all thin rusted steel. Do not let grinding sparks fly freely to damage your chrome, plastic and glass.
Make a patch and trim it until it is .023 smaller than hole. Welding wire gap around all edges.
Position and hold in place with magnets.
Tack in place.
Weld solid.
Cover with seam sealer.
Wire wheel clean.
Prime and paint with any color available.
Lay carpet back over top.

It is a floor!

If you are not concerned with replacing the whole panel, a patch is way better to do. Original steel is in place already.