A Beginning Welder tackles Floorboard Repair, sets car on Fire - PeachParts Mercedes-Benz Forum

Carrameow · #1 02-15-2006, 10:57 PM

Truthfully rhe car caught fire 4 or 5 times. Welding is not for the squeamish. After each welding pass, the undercoating would start to burn, but I used a small spray bottle to extinguish it. I don't think the neighbors were thrilled. Boy I learned a lot after today! I know it doesnt look great, but actually the underside looks a lot better. I used 4 different peened sheets to repair the rot. (One was for the rocker, one for the floor, one for the inside edge and one for a bracket) I guess I dont have to worry about my Toy Fox Terrier falling out of the car anymore........... THANKS LARRY BIBLE( the man who taught me how to do my first diesel engine rebuild also)

Here is the rot

The rot ruined three places, the rocker, the floor and the inside panel. The passenger side seat was imperiled

This is my new Toy, I go down to the garage at 2 in the morning and
drink milk and stare at it...

Just the floor and rocker

Now the inside panel

Finished. HE HE THE PICTURES ARE LO RES BECAUSE THE WELDS WERE TERRIBLE, I GROUND THEM DOWN and REWELDED THEM. The only thing I am proud of is the peening and forming job I did on the sheet metal, it took some patience...

kmaysob · #2 02-15-2006, 11:02 PM

"This is my new Toy, I go down to the garage at 2 in the morning and
drink milk and stare at it..."

haha i do that alot. how do you like the gas vs. flux core? i havent gotten my bottle yet. i plan to get it after my b-day

looks good. i havent caught anything on fire yet. you need to build a welding table to do small prodjects on. i would be lost without mine.

blueranger · #3 02-15-2006, 11:15 PM

i told you guys you pop rivet the floors in instead of weld them..
they always catch on fire.... and aircraft are pop riveted together
so it does work...

Nate · #4 02-15-2006, 11:22 PM

Good job, welding on your cars a good experiance... Cant imagion the look on any passers by with u welding on a benz, and setting it on fire.

Whats fire hurting anyways?

Cut your undercoating back a bit more, and its allright

~Nate

kmaysob · #5 02-15-2006, 11:23 PM

Quote:

Originally Posted by blueranger

i told you guys you pop rivet the floors in instead of weld them..
they always catch on fire.... and aircraft are pop riveted together
so it does work...

i agree, pop rivets do work,but maybe he wanted to weld them instead, or maybe he doesnt wanna ever see the pop rivets. so what if it caught fire. its easily put out. if i ever again do sheet metal work on any of my cars i will weld them instead of riveting. but thats just me

bgkast · #6 02-15-2006, 11:26 PM

Aircraft aren't made of steel. If you rivet water will work its way under the overlap and more rust will form, can't happened with a butt weld.

imdavid28 · #7 02-16-2006, 12:07 AM

Quote:

Originally Posted by kmaysob

i agree, pop rivets do work,but maybe he wanted to weld them instead, or maybe he doesnt wanna ever see the pop rivets. so what if it caught fire. its easily put out. if i ever again do sheet metal work on any of my cars i will weld them instead of riveting. but thats just me

After I got my welder, I wanted to weld everything in sight, even if not neccessary.

I think its good experience. That and it's fun!

blueranger · #8 02-16-2006, 12:13 AM

some one said that water would get in between the rivets..
that is not true... many of the modern cars are glued together
rather than welded... there are highly advanced glues you would
use between the pop rivets... and it would be as good as a weld
and save burning up the car...

kmaysob · #9 02-16-2006, 12:38 AM

maybe so but this isnt a new car. it isnt held together with glue and the cracks and gaps arnt filled with bondo.

unkl300d · #10 02-16-2006, 12:39 AM

Carrameow, thats quite the 'cat's meow' of a job !! boy that was alot of rot. Sloppy Beer drinkers in the back seat???

wbain5280 · #11 02-16-2006, 01:03 AM

You're really supposed to sand/grind off the undercoating and paint from around the weld area so there's no contamination or fire. Pop-rivets work well on aluminum aircraft but not on unibody steel cars. If pop-rivets were better, car manufacturers would be using them. Ships are welded not riveted together, except for a few older lake boats that haven't been scrapped.

Carrameow · #12 02-16-2006, 09:04 AM

Also a lot of this work was done during the Blizzard we had last week

leathermang · #13 02-16-2006, 10:02 AM

Blueranger, You might as well give up on this. These guys WANT TO WELD even if it is not technically the proper fix for this particular set of circumstances...for several reaons. They insist on using the word Pop Rivets even when someone says Rivets...They will not consult with engineers who deal with this kind of restorations or even the standard books on sheetmetal repair...
They insist on butt welding when it should be plug welding into holes punched into the new metal. Plug welding most closely reproduces the Resistance ( spot ) welds used to contruct the car in the first place...
I am only posting this for future reference in case others want to check out the reference materials already published. These guys have already made up their minds... but we tried right from the first...
They are willing to completely ignore the fact that taking the metal to welding heat... particularly where they are not protecting it from oxygen on the backside of the weld changes many important characteristics of the type metal chosen for this job by the manufacturer.

Richard, When you set your dash on fire... I told you to go get a CO2 fireextinguisher.... you really need one for the safety of the whole neighborhood.
It has to be CO2 to be practical for auto repair... you can use it a little at a time because the valve will reseal... and it does not put out a huge amount of stuff which will have to be cleaned up...

" Ships are welded not riveted together, except for a few older lake boats that haven't been scrapped."--Warren

That pretty much shows that the rivets worked.... those are the ones NOT scrapped yet... LOL

imdavid28 · #14 02-16-2006, 10:39 AM

Yeah, but who has a spot welder?????

I think the fun to cost side of the equation is definatly towards the mig as well

1) rivits - cheap - extreamly boaring

2) adhesive - cheap, if you steal some from your UAW job. Otherwise where are you finding it??? - fun if you still like making maccaroni pictures ( I do!)

3) Spot Welder - bout 3 times as much as a mig, and very limited use - cool because it looks like the jaws of life, but I am sure it gets pretty akward quick

4) Mig welder - expensive, but less than a spot welder - wicked cool fun! you can even have stories about how you caught things on fire, and tell your buddies how manly it was.

After all, isn't a hobby like fixing up old cars yourself supposed to be fun?????

Pete Burton · #15 02-16-2006, 10:59 AM

I find new uses for my MIG all the time, and I can't imagine why I would have or could have done 1/2 the jobs with twice the effort if I was riveting. I'm sure it has its place, but no riveter matches the versatility of the MIG for automotive repairs. When was the last time you saw anyone repair a cracked exhaust pipe with rivets?