MonteCarloSS.com
MonteCarloSS.com

CELEBRATING 20 YEARS!

Previous Thread
Next Thread
Print Thread
#493706 - 10/17/07 06:40 PM Repairing Rusted out floors  
Joined: Jul 2003
Posts: 8,174
tonys57chevy Offline
10+ Year
tonys57chevy  Offline
10+ Year
Member

Joined: Jul 2003
Posts: 8,174
little egg harbor nj
Now I don't know the extent of the rust on your car but in order to do a solid repair you're going to find that you will have to remove metal about an inch or two beyond where it is rusty. Normally where you see the rust and holes, the metal is bad underneath the paint.

It's best, if you have the room, to completely remove the seats, carpet and the lower interior plastic (kick panels and sill moldings) If you can, unbolt the seatbelts as well, but most times those bolts just don't wan't move so you may have to cut the carpet around them.

With a good view of the floor you can inspect the frame inside the car. It's very important that the framing is in good shape. If the rust is right into the framing in these areas, it's quite possible the whole car's body is distorted. You should be able to tell by the way the doors close and line up.

Sounds like loads of work but believe me it's better to do all that, then patch it up from the outside only to find the frame inside is shot down the road. When doing this kind of work this stage is sometimes causes me to change it all on the car.

The way I look at it, if the framing is still good inside and out, any car is repairable The framing also gives you something to weld to.

When I patched floors, on one car driver's side floorpan right up underneath the pedals was bad. I got my saws-all out
( sameone i use to cut up car i use to fix them lol ) and began to cut all the bad stuff out. I found I had to go about an inch beyound the rust all around. If your car is bad around this area and the otherside be sure to inspect where the K-frame joins to the frame rails underneath and look at the rear of the frame rails to see they are still solidly attached. When you start cutting out the rust make sure you are careful not to cut something on the other side too!! I allmost went through a brake line on one car.

I used metal from the roof of an old car that I had saved before I scrapped it.I also have use pans out of parts cars. But it is best to buy a new or rust free pan to put in. This metal is normally of heavier guage and works well for this kind of job. I used a little 110volt mig welder to do my floors, its the best tool you could invest in believe me, but I'm sure you could torch weld the floors in too.I just don`t like to do it that way.

As for heat distortion, when you weld in the patch weld them in spots. I spotted every inch on mine and never warped anything. The cars are put together with spot welding anyway. You just have to make sure you seal both sides of the repair when you are done. Doing it this way, makes forming the floorpan easier too. You can use the heat from your previous weld to pound and shape the next spot. Be sure to cut your patches bigger then the spot you want to fix as well. Don't be afraid to overlap in areas either.

If you do have to replace the floorpan metal running over the two main frame rails.. be sure to weld the patch to the flange on the rails too. The floor pan does help stiffen the chassis.

I don't like saying this to anybody, but if the framing is in really bad shape, rob what you can in parts and get another car. This was done on a 40 chevy.





Pres. Wicked Rides car club,member of NJMCC,NYMCC
1983 Monte Carlo Convertible white, 1983 Monte Convertible red
1983 Monte Convertible white, 1983 monte convertible white
1957 Chevy
85 SS, 86 SS 8,272 miles
www.wickedmontes.com www.wickedridesnj.com
#765522 - 02/14/10 05:46 PM Re: Repairing Rusted out floors [Re: tonys57chevy]  
Joined: Jul 2003
Posts: 8,174
tonys57chevy Offline
10+ Year
tonys57chevy  Offline
10+ Year
Member

Joined: Jul 2003
Posts: 8,174
little egg harbor nj


new one welded in and sean sealer around it


this is not my floor


Pres. Wicked Rides car club,member of NJMCC,NYMCC
1983 Monte Carlo Convertible white, 1983 Monte Convertible red
1983 Monte Convertible white, 1983 monte convertible white
1957 Chevy
85 SS, 86 SS 8,272 miles
www.wickedmontes.com www.wickedridesnj.com
#968474 - 04/12/13 04:03 AM Re: Repairing Rusted out floors [Re: tonys57chevy]  
Joined: May 2007
Posts: 5,043
Buick Runner Offline
10+ Year
Buick Runner  Offline
10+ Year
Member

Joined: May 2007
Posts: 5,043
Dharma station 1 the Hydra
Very helpful info here. Here are a few things I would like to add, these cars are built with mild steel, which makes them easier to weld and is safe to use a torch on them, both welding or brazing. More modern cars use high strength steel that cracks if you try to torch weld or braze it.

When buying a welder, be sure to get a namebrand like Lincoln or Miller. I have a Schumacher MIG welder, but I can no longer get parts for it so it is now useless $400 box.

Welding thin sheet metal is the hardest type of welding to learn since it easy to burn it. So you may want a welder with infinite heat settings instead of a cheap model that only has a couple of heat settings.


SBC powered 1987 Regal with TES headers, ZZ4 intake, ZZ4 PROM chip, mini starter, THM2004R, 2500 stall converter, 2040 cam, CCC system, and 3.73 posi rear.

2008 ex NPS P71 Crown Victoria, cop motor, cop shocks, cop brakes, and Jmod.

Never argue with an idiot.
They will just drag you down to their level and beat you with experience.
#968541 - 04/12/13 09:55 PM Re: Repairing Rusted out floors [Re: tonys57chevy]  
Joined: May 2009
Posts: 2,012
Richie Cat Offline
10+ Year
Richie Cat  Offline
10+ Year
Member

Joined: May 2009
Posts: 2,012
Lake Ronkonkoma, N.Y.
And don't use flux core wire in the mig. It's hotter and can burn through easier on light gauge metal.


83 SC, 355 w/TPI
#969417 - 04/21/13 05:52 PM Re: Repairing Rusted out floors [Re: tonys57chevy]  
Joined: Apr 2013
Posts: 12
fpesc Offline
Junior Member
fpesc  Offline
Junior Member

Joined: Apr 2013
Posts: 12
Middletown RI
where did you get the rear floor pan? How much did it cost to weld it in?

#969941 - 04/27/13 03:10 PM Re: Repairing Rusted out floors [Re: tonys57chevy]  
Joined: Jul 2005
Posts: 2,671
gmachinz Offline
10+ Year
gmachinz  Offline
10+ Year
Member

Joined: Jul 2005
Posts: 2,671
Des Moines, Iowa
Besides actual floor rot, the most common problem I run into is rotted out body mount locations resulting in completely rebuilt mounts being required, which I build using heavier gauge steel and I mimic the adjustable feature of the mounts but build them much more stout since aggressive handling will tend to flex these areas much more. A lot of people overlook the importance of stout body mounts.

Good read on the floorpans....agreed-no fun but worth it in the end...., well-I have fun doing them but that's the oddity in me...lol.


gbodyparts1234@yahoo.com

HARNESSWORX
#970247 - 04/30/13 03:21 PM Re: Repairing Rusted out floors [Re: tonys57chevy]  
Joined: Jul 2003
Posts: 9,209
SickSpeedMonte Offline
15+ Year
SickSpeedMonte  Offline
15+ Year
Member

Joined: Jul 2003
Posts: 9,209
MD
If you Google Conrad Lozier, he can ship you new body mount pockets for the #6 and #7 locations.

#973441 - 06/01/13 05:11 AM Re: Repairing Rusted out floors [Re: tonys57chevy]  
Joined: May 2007
Posts: 5,043
Buick Runner Offline
10+ Year
Buick Runner  Offline
10+ Year
Member

Joined: May 2007
Posts: 5,043
Dharma station 1 the Hydra
Another hint is use name brand welding wire or rods! The cheap stuff is made from scrap metal and is harder to work with and gives poorer results. Even with a cheap no name brand machine, don't use the wire or rods it comes with, use name brand in the machine and it will perform better.

Also if you want a MIG welder, get one with cold start, it makes welding much easier.


SBC powered 1987 Regal with TES headers, ZZ4 intake, ZZ4 PROM chip, mini starter, THM2004R, 2500 stall converter, 2040 cam, CCC system, and 3.73 posi rear.

2008 ex NPS P71 Crown Victoria, cop motor, cop shocks, cop brakes, and Jmod.

Never argue with an idiot.
They will just drag you down to their level and beat you with experience.
#973774 - 06/04/13 10:36 AM Re: Repairing Rusted out floors [Re: tonys57chevy]  
Joined: Oct 2006
Posts: 1,799
JAWSS Offline
Member
JAWSS  Offline
Member

Joined: Oct 2006
Posts: 1,799
Ft. Hood, TX
I bought a Lincoln 180HD MIG Welder from Home Depot. It is also available at Lowes. I love this machine. Even with flux core wire you can easily control your heat and not burn through even with thin metal. It is reasonably priced and is able to run off of most 220 dryer plugs and has provisions for 75/25 or flux cored wire. I finished a nice little project with it recently.



86 Monte Carlo SS T-top
69 Cutlass S Convertible
70 Chevelle Malibu (Second owner, grandma car)
12 Cadillac CTS-V Wagon
#974026 - 06/06/13 05:39 PM Re: Repairing Rusted out floors [Re: tonys57chevy]  
Joined: Jul 2003
Posts: 9,209
SickSpeedMonte Offline
15+ Year
SickSpeedMonte  Offline
15+ Year
Member

Joined: Jul 2003
Posts: 9,209
MD
Wait till you get a gas setup on that thing. That is very close to the 190 Hobart Handler that I use (Hobart is owned by Miller so most of the parts even interchange.)

For 20ga butt welding, I put the power on '1' out of 7 (~27A I guess? I wish it was a rheostat instead of a discrete switch) and the wire speed on ~25 out of 100. I use 75/25 and .024" wire, and that seems to work very well. I put the gas on ~21 lb/hr, I think I saw that on youtube somewhere. Maybe I could go lower, I never get contamination or pitting. Welding on metal that thin, I listen more than watch because it's hard to see and you can burn through so quickly. I usually put a tack weld for about a second (maybe a little less) after I get a nice buzz sound. If it is popping, it's not welding the base metal, only making a puddle of filler wire which can pop back off. The buzz sound gets higher frequency as you come closer to burning through, so if I am laying down a series of tacks and I notice that the buzz is getting higher pitched, I'll pause for a second before moving on to the next one.

If I am lap welding something, I go up to 2/7 and maybe ~30 on the wire speed. After getting a feel for it, I usually get a nice puddle on the back side of the metal that looks just like the front. Then I take a 36-grit flapper wheel and knock down most of the weld, stopping before getting to the base metal. It leaves a little raised, but I'd rather have it be strong than look perfect under the carpet or wherever.

This was all for floors which are forgiving because of the bracing stamped into them which gives them rigidity. If it was something that really needed to retain it's shape, I've had good luck with hammer welding, where you weld and then hammer-on-dolley (the dolley is directly behind the blow) while the metal is still red. This is supposed to release the stress caused by the weld and stretch the metal back out (welding shrinks it). I welded long flat repair patches to my wheel wells that way and ended up with almost zero warping. It's long and tedious, but quicker than trying to straighten out a warped panel.

Flux core wire tends to burn hotter because there is no forced gas flow around the weld to cool it. It also leaves slag that must be chipped off afterwards. With sheilding gas, I get a little bit of what looks like brownish soot that comes off easily with a wire brush.

I have a "Hobart Hood" auto-darkening welding mask that worked great for a year. Now, once in a while, it will fail to darken, and that gets your attention. I have changed the clear shield that goes over the sensor/window, replaced the batteries, and it still does it once in a while. I've also noticed that when you turn it on, it is supposed to flash dark twice but sometimes it goes dark and then very slowly comes back to light. IDK what's going on with it. One more trick... I took a "headlight" (straps to your head, like a miner) and strapped it to the hood. The one I got has an adjustable angle (up/down). This is *extremely* helpful in most situations where you are welding on the car and not at a well-lit bench.

#978490 - 07/22/13 12:00 AM Re: Repairing Rusted out floors [Re: tonys57chevy]  
Joined: Apr 2011
Posts: 86
monte_man_2020 Offline
Member
monte_man_2020  Offline
Member

Joined: Apr 2011
Posts: 86
Lisle, IL
I bought my welder at menards (don't remember brand) but it worked good forme doing the corner over by the hood latch on the driver side. I'll have to post my pics before and after. Did some more welding on other parts of the floor, tossed the carpet, and rhino lined the whole floor (especially underneath where I welded, don't want my work ruined).


Random Images
854/thumbs/100_7995.JPG
by FuzzyDnkn
500/thumbs/monte56.jpg
by tovann
1130/thumbs/ResizedImage_1390834189346.jpg
by O.G.
500/thumbs/monte_7.JPG
by Monte83
500/thumbs/IMG_1450.jpg
by Billdo38
Help MonteCarloSS.com


Recent Contributors
86BlackSuperSport
dns87ss
Authorized Vendors
Tell them you saw it
on MonteCarloSS.com!


CustomMonteSSParts.com
Dixie Monte Carlo Depot
GSI Interiors
HRpartsNstuff
Mikes Montes
Savitske Classic & Custom
Powered by UBB.threads™ PHP Forum Software 7.6.0