Buying a welder

[sewebster]

So, I have some holes in my floor (gas pedal, under rear seat, rear cargo area) and it seems that I can get a used welder on craigslist for the same or possibly less than it would cost to get a shop to fix it. As a bonus I might learn something about welding. Since it's just the floor I'm not super concerned about doing a bad job, plus I have some friends who can likely help.

 

Anyway, I have minimal storage space and was thinking what I would do is try go get something small (120V) and just use some flux core wire. Looking around it seems like what I need to do is get a small mig machine and then just not use gas (gives option for later)? I haven't noticed the option of not getting a gas setup at all (the "stick" setups are all inappropriate for sheet as far as I know).

 

So, looking at the small migs (which I see are available for as little as a few hundred bucks used, more like $1000 new), they mostly have spool guns as options. I guess this is a dumb question, but how do you feed any material without the spool gun? Is there a separate wire feed that I just can't see that is associated with the gas nozzle/trigger? Do I need a spool gun for my simple starting out setup?

 

I know a bunch of people here sing the praises of the ready welder, but then I still need a power supply...

 

Any tips welcome, I tried searching btw

[87pathy]

for doing sheet metal that would be fine.

 

if your going to do any "fab work" you need a 220 machine, but don't get a stick welder if your doing sheet metal and just learning.. VERY difficult.

[BoneZ]

I Do not recomend linked welder for any true metal fab but have found it to be a cheep great machine for doing sheet metal jobs and can be bought new for under 100 allot of the time.

cheep welder

In the link posted it is a little over 100 but I have seen them go on sale as low as 80 dollars. But you need to take the flux core wire that comes with it and throw it in the trash and go buy some lincon or miller flux core wire to put in it. The cheep wire that comes with it dose not penetrate well and splatters everywhere.

[sewebster]

Thanks guys. Did some more reading and now understand that I don't really need a spool gun at all for what I want to do now. It looks like they probably just make wire changing easier and are important for softer metals that won't feed the long distance inside the regular gun/cable.

 

That cheap welder looks tempting, though sometimes I don't have the best luck with cheap tools No Harbor Freight up here in Canada. I could get one from the US but it does add some hassle to deal with the border (esp. if I want to return for warranty).

Edited June 7, 2011 by sewebster

[lint]

Go to Princess Auto (Coquitlam), Summit Tools Burnaby, or even better, KMS Tools (by Ikea, Coquitlam). Look around, compare models, prices. It is always better to buy "name brand" or quality tools rather than "cheep" tools based on price.

[sewebster]

It looks like I'm going to be picking up a used Millermatic 135 tonight. It seems like it should be good for my purposes, and will be cheaper than anything new from a "reputable" manufacturer

 

Now I need to figure out if I can get away with flux core to repair the floor (will I be blasting through?) and need to decide how much to spend on a helmet (do I need variable shade when all I've got is this small welder?).

[Precise1]

I've heard the arguement that an autodarkening visor is better for a novice, meaning that you will be all lined up and in position and just start welding; ie you'll get better results.

 

B

[sewebster]

I've heard the arguement that an autodarkening visor is better for a novice, meaning that you will be all lined up and in position and just start welding; ie you'll get better results.

 

B

 

Yeah, I agree, I'm pretty sure that I'll get terrible starts to the weld if I have to do the starting blind, so I want auto darkening. However, the cheapest auto darkening helmets ($100-$150) just switch to shade 10. If you pay more ($200-$250?) then you can get a variable shade autodarkening, which goes from 8-13, allowing for proper vision during a wider variety of welding processes.

 

But I don't need to have a helmet for welding the golden gate bridge, just something for using this small 115V mig. So maybe the cheaper one would be fine. I looked at a table and I think that maybe I can get away with shade 10, but I am a novice...

 

In an ideal world I'd just get the $2000 helmet that comes with all the doodads, but, then I'd be spending more than $350 on a welder...

[Precise1]

Check these out...

 

 

 

B

[sewebster]

Sounds like the way to go for me is to somehow get one of those $50 ones. But I haven't even seen a non-auto-darkening for that little so far in my search up here in the great white north. Need to look harder and/or go to the US.

[jj big shoe]

I grabbed a $50 auto-darkening helmet but haven't used it yet. I'm sure it'll be better than the Kabuki mask looking hand-held one that came with the welder.

It's been my experience welding on the Pathy's body that you will easily blow right through the metal for three reasons:

 

1. I'm a crappy welder

2. The sheet metal they used is pretty thin

3. There's usually a tad more area affected by the rust than you can tell (surface rust will still thin the metal)

 

Good idea to practice on the floor but if you end up blowing through you might want to patch the pin holes with silicone and call it a day.

[sewebster]

I grabbed a $50 auto-darkening helmet but haven't used it yet. I'm sure it'll be better than the Kabuki mask looking hand-held one that came with the welder.

It's been my experience welding on the Pathy's body that you will easily blow right through the metal for three reasons:

 

1. I'm a crappy welder

2. The sheet metal they used is pretty thin

3. There's usually a tad more area affected by the rust than you can tell (surface rust will still thin the metal)

 

Good idea to practice on the floor but if you end up blowing through you might want to patch the pin holes with silicone and call it a day.

 

Yeah, I'm mostly worried about your #1. I hope to realize that #3 is an problem and cut away more material than might be obvious until I find some good metal. I still need to figure out if I'm less likely to punch through with 24 thou wire and shielding gas or if I could use 30 thou flux core.

 

I don't really know much about welding on vehicles. Do I need to unplug the battery or anything? My plan is to cut away the rust, prep the metal with a grinder (maybe flap wheel), tack a sheet in place, heat with oxy-acetylene and hammer to form into the proper shape, and then weld around the edges where it should now all be in contact. I'll be doing this from the top with the carpet and seats out. Ideally I won't end up with any overlap on the bottom, because I figure that would rust like crazy. I guess if I start blasting through then I'll have to solve the problem, but realistically the problem won't be much worse than it is now

 

Does anyone know the thickness of the sheet used in the wd21 floors off hand?

[jj big shoe]

I think its 22 or 24 guage. I fixed the floor in mine before I had the welder using rivets and silicone gasket maker. I had to replace the entire floor under the rear seat plus a couple places the size of a keyboard and I guarantee it would've been much harder if I had tried to weld it. Running a continuous bead around a patch panel is harder than it sounds. You have to do a series of spot welds really, going around the patch panel until all the edges are welded. Very time consuming and difficult when you're sparking on old metal. I've done a few patches on my rocker panels and it took quite a while (then again, refer to #1 in my previous post).

 

For the floor under the rear seats I cut the old section out then formed some 22ga sheet metal to overlap about an inch, drilled a rivet hole every two inches (150 rivets or so), goobered the overlap up with gasket maker to keep the water and grime from collecting in the seam and set it in place. I used fiberglass patches around the wheel wells since its near impossible to make those bends out of metal without the proper tools.

Edited June 9, 2011 by jj big shoe

[sewebster]

Yeah, I kinda realize that this isn't necessarily a trivial task. I previously considered the rivet route. I think the main reasons I still got a welder are: I want to learn to weld, I worry about any filler I put in the seams failing under heat from the exhaust, and I need to weld up some new cups for my front suspension rods too. Sounds like your usage of silicone will be heat resistant, but then you can't really paint it I guess. Maybe that doesn't matter.

 

How did you deal with all the junk under the seats was anything hard to get in the right place? Maybe the only things that you need to have there are the seat belt which isn't precise and the parking brake cable which also doesn't really matter. Dunno if the seat hold down clamp thing is important for safety or not? Seems like that could be hard to place right.

[adamzan]

Nismojunky did my floors but he showed me how to weld sheet metal in the process and once you get the hang of it, its not that hard. The welder we used was an 80 amp fluxcore crappy tire job that I picked up on sale a few years ago. Works good enough for what I need to do. Also don't use silicone or caulking on the floor go to an auto body supply place and get some seam sealer it cures hard but actually adheres to the floor not like the other stuff that peels off really easy. I am by no means an expert this is just my experience so far. Here is the floor job:

I cut out ALL the rust at least an inch around it. I also seam sealed it from underneath. Don't get that stuff in your hair, it sucks.

[sewebster]

Don't get that stuff in your hair, it sucks.

 

 

Does that stuff hold up to heat from the exhaust below? I assume you put that on because you just tacked it down all the way around instead of a continuous bead.

[adamzan]

Yeah it holds up to the heat great, its actually what you're supposed to use when sealing floors (well thats what the body shop place told me). We did stitch it all the way around and close together, you're not supposed to run a bead on sheet metal because it will warp. You have to stagger the welds when doing it.

[sewebster]

Yeah it holds up to the heat great, its actually what you're supposed to use when sealing floors (well thats what the body shop place told me). We did stitch it all the way around and close together, you're not supposed to run a bead on sheet metal because it will warp. You have to stagger the welds when doing it.

 

Cool. Yeah, I figured that just running all the way around would not work. I guess the question is, once you have it basically all stitched up close together, should you seal it like you did, or "fill in the gaps" with the welder. Maybe using the sealer is just easier, or maybe filling in the gaps is just asking for trouble with burn through or something.

[adamzan]

I had part of my truck repaired at a body shop a few years ago because someone had hit it at one point in time and though it was "repaired" it had started rusting at post at the drivers footwell. So much so that the door moving flexed that whole corner. I watched the guy do it and he did exactly what we did and he's been doing it for like 40 years so I guess it must be the most efficient way.

[sewebster]

I had part of my truck repaired at a body shop a few years ago because someone had hit it at one point in time and though it was "repaired" it had started rusting at post at the drivers footwell. So much so that the door moving flexed that whole corner. I watched the guy do it and he did exactly what we did and he's been doing it for like 40 years so I guess it must be the most efficient way.

 

Hehe, yeah, probably emulating a pro isn't such a bad idea Thanks.

[adamzan]

No problem. I'm no pro just a skeptical guy who doesn't trust shops so I have to do it myself. Plus its cheaper.

[jj big shoe]

How did you deal with all the junk under the seats was anything hard to get in the right place? Maybe the only things that you need to have there are the seat belt which isn't precise and the parking brake cable which also doesn't really matter. Dunno if the seat hold down clamp thing is important for safety or not? Seems like that could be hard to place right.

I still don't have rear seat belts. I did however mount a couple U-bolts so I could secure my son's car seat. The seat bottom clamps never really worked in my truck anyway so they weren't a problem. Neither was the E-brake since I didn't chop that area up.

Yeah, seam sealer is prolly a better way to go, but my repair is holding up well so far.

[Slartibartfast]

When my uncle welded up the holes in mine, he went all the way around (spot and fill) with no sealer, except for the undercoating I'll be putting on soon. We used floor bits cut from a wrecked 93 at the local yard (cut a bit bigger than the holes for overlap). He used the wirefeed he uses for everything from thin sheets to frame steel. The patch wasn't cheap, but it looks good.

 

One thing to look out for, the old undercoating (unless yours has all fallen off) will try to catch fire from the weld heat. We put a hose underneath the truck with a sprinkler sort of thing on the end to keep it cool under there.

 

(Luckily the seatbelt mounts and all were fine, so we left them alone. Since we were cutting bits from a wrecked Pathy anyway, we would've just taken the brackets out.)

Edited June 12, 2011 by Slartibartfast

[Trogdor636]

The above technique is the best way to really do thin sheetmetal. If you find the metal getting too hot, just take your time, or keep a wet towel around and apply it after you do a tack. Just continue to do little tack welds until it is basically a continuous bead all the way around. For a novice just beginning to weld, just get some scrap metal and practice, practice, practice. Welding is awesome when you get the hang of it, but sometimes its frustrating to understand until you burn through a couple spools of wire.

[sewebster]

I did end up getting the Millermatic 135 I mentioned above... I'm trying to practice, but it's hard to find time, and since I end up doing this outside, I need to be careful that no random people wandering around can get flashed. I also got a 20 cu ft bottle, because I have very little storage space, but I'll run through that really fast with a lot of practicing. It will be good in the long term though, since I won't really be doing all much welding (I figure it's 45-60 minutes worth).