How to deal with this rust on fender

[yolner]

I'm starting on the rust on my truck and to practice I'm stripping down a fender. I found a couple of rust holes. Problem is that under that hole there is another piece of metal that's not rusted through. What's the best way to deal with this type of rust?

Pictures: imgur: the simple image sharer

 

[camoyj7]

Use a cut off wheel and just cut out the top part that is rusted. Make you patch and weld it in.

 

[dmetalmiki]

Have you a smallish electric welder? well worth getting one if not. I have a new Electronic COVERTER welder. Exellent..and Small light and definately easir to use than the conventional mig welders. Its only about 24x10 inches and BEATS my HUGE mig (that weighs about 2 tons!!) all ways up for working on my military hobby stuff. from fenders to bumpers.

 

[4x4 Forever]

Crop out the old and put in new.

 

[yolner]

Thanks for the info. I guess I'll finish stripping and start cutting.

 

[lawdog1623]

you did an excellent job cutting the cancer out. I went to home depot and bought the lincoln electric mig 180 hd weldpak. I took my die grinder and started cutting sections of the rust that i could find. My cab was relatively good and didnt need any patchwork. The bulk of the rust was on the cowling in front of the windshield. I cut that away and went to buy a few medium sized squares of sheet metal. Then i found an anvil that a friend had laying around and shortly thereafter purchased a cutting torch kit (small bottle portable type). I cut out patch pieces of sheet metal and shaped them with a torch and anvil. I then welded the pieces in and grinded down the weld. I then spray painted the spots with duplicolor od green self etching primer and it will sit that way until i paint it in the next month or so. Its pretty labor intensive but you can do it. The excuse i used with my wife was that i needed a welder to use for odd jobs around the place. I spent a little over 1000 on the tools, but im much happier with having done the work myself as opposed to paying someone else to do it. The welder was great, and i had absolutely no experience as a metal fab guy.

 

[Katahdin]

Yep, I had to do something similar and I'll be welding in some new patches in the near future on the 109 box.

http://www.steelsoldiers.com/paint-bodywork/68331-first-attempt-replacing-metal.html
Pics of end result on bottom of page 2, still looks great a year later.

 

[m16ty]

Don't forget to treat the metal under your patch to keep it from rusting more. You'll damage whatever you put under there some when welding but anything beats nothing at all.

 

[RAYZER]

If you need to use a body filler, use a fiberglass strand filler like kitty hair, bondo also makes one. These won't absorb water like regular bondo filler Will.

 

[3dAngus]

While on this subject, what kind of welder would be best fit to handle this job on sheet metal. I've never welded before, but went to NASA soldering school, so I know a little something about cleaning and the basic principles involved. I've used a Lincoln arc welder once and was unimpressed with my work. I read and watched a video about how to use your ears when welding with it, and could hear the difference, but need further practice.

Now, I would like to buy a welder for a toy and practice, but wonder what kind would be the best overall selection for a newbie who wants to work on steel.

I dunno, maybe I'll build a bridge or something.

Anyway, any suggestions on what type I should start out with would be appreciated. Maybe a Northern Tool or Harbor Freight tool. Acetylene may be out of my realm. I need something I can plug in. Thanks in advance.

CamoyJ7, that is a fine cut. What did you use to cut that out with. Nice work!

 

[camoyj7]

While on this subject, what kind of welder would be best fit to handle this job on sheet metal.

CamoyJ7, that is a fine cut. What did you use to cut that out with. Nice work!

I have a 120 amp mig with .023 wire i use for sheet metal. I like the thin wire for sheet metal because it takes less heat to melt. When welding sheet metal I put a tack weld every few inches to keep it from warping. Then go back to where you started and put a tack right next to the other tacks. Keep doing that until the piece is fully welded. If you did a continuous weld you would warp or melt away the sheet metal. I used a .040 thick cut off wheel to cut the hole in my fender. I always use the thinnest cut off wheels i can get. They cut faster and they don't put as much heat to the metal.

 

[m16ty]

I like to use a TIG welder to put on patches. A MIG will work fine though.

It just seems I can do a nicer job with the TIG and not need as much filler to smooth it out when I'm done (if I need any filler at all).

Novice welders need to stick with MIG. It takes quite a bit of skill to run a TIG bead and be good at it.

 

[Welder Sam]

MiG units are probably the easiest for a novice. They come in 110,220, and dual voltage models. Seems as though Miller has deticated their line of small units to the novice with auto set or something like that. U tell it the thickness of material being welded and it sets the voltage and wire speed. Check with your local welding supply shop, not home depot or lowes, for these. Im looking to purchase a mig machine myself in the near future but ill probably go with a lincoln or maybe hobart because i want it to run how i want not how a book says. Good luck in your welding.


Advice: DONT MAKE IT A PROFESSION

 

[Katahdin]

You can set the wire speed and voltage manually on the Millers, in fact autoset only works with two wire thicknesses depending on the machine. On my 211 autoset only works with .30 and .35 mig wire. For anything else: .23 Mig, flux core, alluminum, etc the only option is to use the wire speed and voltage chart.

 

[Welder Sam]

Wow they send charts with'em? Ive never bought a wire machine, just used a bunch in my 16yrs in the industry. I guess my prtable rigs came with something similar seems like. When it comes to thin materials, i like. 023 hard wire with 75/25 or tri-mix in a single phase

 

[Ferroequinologist]

I love my hobart 180. Works great, best $300 I ever spent. I've used it so much the drive rollers are wearing out, has a hard time pushing the wire through the lead now. Have to see about getting some new ones.

 

[Welder Sam]

Thats about the amps im looking at. Not to be offensive but.. Have u changed the liner?

 

[Ferroequinologist]

Nope, didn't even realize they had a liner! I just noticed the grooves in the drive wheels are worn. I will look into it, thanks!

Yeah the 180 is great, will do low enough amps to do sheet metal but will also do 1/4 in steel in one pass.

 

[meangreencustoms]

I agree with Ferro, I have a Hobart 187 and I have run the grooves out of mine. I need a new liner as well, but instead I will change out the gun to a 25ft model. I use mostly .30 or .35 Flux core only because I weld outside with alot of wind, so the gas is almost useless. I am working on setting up screens to block the wind an go back to tri-mix and solid it looks so much better when I am done, plus you can see the puddle so much better.

I say go with a low amp 220 model for your first mig.

FYI my Hobart is a Miller in sheeps clothing. Some of the parts even have Miller on them, for example the gun is a miller. The rollers are Miller too.

Terry

 

[plym49]

The original fenders on my Deuce are swiss cheese. I picked up a set or replacements that need the same repair illustrated in this thread. I have a Millermatic 200. What setting and wire speed would you all recommend for patching Deuce fenders?