I need to get a small (read that cheap!) welder for some projects. Basically I need to weld some small pieces of cast iron together. What would be the best little welder to pick up? thanks!!!

-- Doreen (animalwaitress@yahoo.com), May 03, 2002

Answers

none,, you cant arc weld cast, need a mig/tig, or you can braze it,, that requires a torch kit

-- Stan (satanswelp@hell.net), May 03, 2002.

Hey Sis! I use an old Miller stick welder with cast iron rods. I get the rods at the local farm store. They're a little bit higher than the old "farmer rods" but well worth the cost if you need one. I run it on as low heat as possible --about 100amp--and weld short distances at a time. It needs to cool off some between welds. If you're weldin a crack--drill a small hole at each end to keep it from crackin any further. OLd hoot. Matt.24:44

-- old hoot gibson (hoot@pcinetwork.com), May 03, 2002.

I was always told you cant weld cast,,,it turns to sand,, they make sticks for cast??

-- Stan (sopal@net-pert.com), May 03, 2002.

You can weld cast iron with nickel rods. It takes some skill but it can be done.

-- Dave (multiplierx9@hotmail.com), May 03, 2002.

Hi guys, I just want to tack pieces of cast iron together. i'm hoping to make some kitschy kind of 'objects des arrrrr t'. It doesn't have to be a weld that will hold up to repeated beating with a sledge hammer or anything. Thanks for your help!

-- Doreen (bisquit@here.com), May 03, 2002.

Unless you follow the advice above than it will not stick --period !! For what you are talkng about ?-- may I recommend a good Epoxy--I use it all the time on such projects. Instead of a 359.00 dollar arc or tig welder you may find 4.59 a little more attractive--and stronger !

-- Joel Rosen (JoelnBecky@webtv.net), May 03, 2002.

I thought of JB Weld, but I need to do almost fifty with a fair amount of variance and since I do indeed want to learn to weld, I thought maybe I could just use a buzz box and kind of get my feet wet with this project. hmmmm. $359!!!!gulpingabitonthatone

-- Doreen (bisquit@here.com), May 03, 2002.

Doreen, I learned how to arc weld cast iron while in the Coast Guard, way back in 1965. It requires a lot more skill than I've ever developed. I also learned to gas weld cast iron with similar results. The welding itself is not that hard (although you have to get the cast iron incredibly hot for gas welding; it's scary, it's so hot). The problem is that the cast iron NEAR the weld is weakened by the heat-it turns into "white" cast iron, or something, and gets really brittle.

I don't recommend either method. On the other hand, I've had great success brazing cast iron. I've done this lots of times, with excellent results. In fact, I've brazed the cast iron on my cement mixer three or four times over the last fiftteen years or so. I've even brazed it right where the handle which you use for tipping the drum attaches to the yoke holding the drum. This has a LOT of force applied when you tip the drum, as the handle gives you maybe a twenty to one leverage advantage. The brazing has never broken, nor has the cast iron near the brazing.

The trick is to use a good torch (oxy-acetylene), get the cast iron hot enough to melt the brass rod, and use good flux. Apply the brass generously.

It's most satisfying to see these welds hold up so well for so many years. You CAN do it! Best of luck.

-- joj (joj@home.org), May 03, 2002.

Take joj's advice, much less heat involved, less distortion and all sorts of other advantages. Also bronze or brass 'welding' is a surface bond and a break in cast iron has a lot of surface area. Joj says use plenty of brass, I usually use the minimum because I was once told the strongest braze join is only one molecule thick.

-- john hill (john@cnd.co.nz), May 04, 2002.

Doreen----you know I'm not mechanical at all!!!!!!! Don't know one tool from another---etc/etc/--- Well I married a welder----I knew he was cause of the hat he wore!! ha!! And his bumber sticker on his truck--said, "Welders do it hotter"--ha! He had lots & lots of welders---all sizes----etc./etc---all kinds of rod---etc/etc/etc-----& a truck with one on the back of it---

When we were first married /he took a job in another town & I would move & join him /when our daughter finished the school year/ where we were & I would quit my job & he would find us a place to live---

Well he was working many hours & long hours----& he would call me at my job & we would discuss/ what I needed to do before the great move-- ----

He told me/ sell anything in the garage for what ever I could get out of it-----

So I had a garage sale & I sold everything /I didn't want to move plus all that "stuff" in the garage----that was hubbys--

He came home with trucks--etc/etc/ to help us move----& said/ sooo where is the welder that was in the garage???????????????

I said /did it look like---such & such--- & he would say---"no"--- then I said----"oh, was it that box thing with dials on it??????????"

He said--"yes it was!!!!!!!!!!!!!!!!!"

When I told him/ what I sold it for------he said ----from then on I could sell anything of his/ I wanted to----I sold it for more/ than he paid for it--- & he had used it for many years-----

But I always remembered-----that the welder had dials on it----& to get the most /I could ---if I sold it!!!!!! ha!!

I still love my hubby in that welders hat--he isn't a welder as his profession any more----but he still has all kinds of those boxes-- with dials on them--!!!!!!! ha!!! Would you like to buy one from me?????????? ha!!! Thought you might enjoy the story-------later Sonda

-- Sonda in Ks. (sgbruce@birch.net), May 04, 2002.

John, that's interesting. I'm pretty homespun in welding, so you may be right. I've had good success my way, though.

Doreen, btw, for really strong brazing joints, I've also resorted to laying a piece of steel across the cast iron's joint that I'm welding. I've used simple things like 16d common "bright" nails, pieces of rebar, scraps of steel, etc.

In a few minutes I'm going to braze a very thin steel tube together, where it broke at a screw hole. It's from my Mom's chair. I'd weld it, only it's so thin I can't do that, so I'm brazing it. I'm going to put a couple or three16d nails running parallel to the tubing, so it won't just break again in the same spot. The screw holes are rather large diameter, in comparison to the diameter of the tubing. Desing defect, I'd say.

If you are really interested in getting a welder, I recommend you get an oxy-acetylene setup first. It's so much more versatile; besides, you'll need one to cut steel before you weld it.

-- joj (joj@home.org), May 04, 2002.

Joj, Doreen, what about a propane/oxy set? We call them 'plumbers' sets, I don't think they are as hot as acet/oxy but ok for brazing and I expect a lot cheaper and I dont think you need the expensive regulators and guages etc. Acetelene (sp?) is not expecially dangerous but there are some critical handling issues.

Doreen just wants to 'stick' some art objects together and maybe a cheap arc set would do that even though the 'weld' would look like deposits of fresh guano.

As an alternative suggestion for the art work you could drill holes in each piece and slip in short pieces of steel rod, maybe even nails depending on the size of your creation. Lock the rods in place with epoxy

-- john hill (john@cnd.co.nz), May 04, 2002.

Good idea, John. I have never had one of these outfits, since I have been using oxyacetylene for almost forty years. I am certain that propane has a LOT less btu's per unit of measure than acetylene, but I've heard that you can braze with the oxy propane setups. However, I don't know if you can braze anything very large or thick. Best, Doreen, to find out more info before buying one. Or take it on approval.

Another possible option: my wife has a little torch she uses for jewelry making. She uses my acetylene tank, but no oxygen tank. It uses acetylene mixed with air. I've only used it to help her cast gold, brass, and so forth, to melt the metal before casting it. I've never tried to braze with it; it does have a pretty hot flame, though.

One other consideration: look at the cost of propane (in btu's) versus acetylene. I know that my acetylene is pretty cheap, by the smallish/medium tank (weighs maybe fifty or seventy-five pounds. Also, if your flame is less intense, it will take a LOT longer to get the stock up to proper temperature. This results in more time spent at your project, and also results in a lot more fuel being used. (If you've got a really hot flame, you don't need to run it for long)

-- joj (joj@home.org), May 04, 2002.

I own and use a torch with propane instead of acetelene. It is just as hot but uses quite a lot more oxygen. The tip is opened up more than the ace. tips. I braze as heavy stuff as with the acetelene gas. old hoot. Matt.24:44

-- old hoot gibson (hoot@pcinetwork.com), May 04, 2002.

"will look like fresh guano" (!) Oh no, really? There are tons of welders around here because of all the oil fields, so I guess what I will do is stop in at the welding supply place and have a chat with one of the guys there and see what they reccommend. A friend was supposed to teach me a couple of years ago, but he started acting like a typical male and he's married, so I just backed off on the deal...sometimes being honorable costs a lot of extra time:). But thanks so much for all of the ideas here. I really do appreciate it folks!

-- Doreen (bisquit@here.com), May 04, 2002.

If you decide to weld with a stick welder, cast needs to be preheated quite hot before welding then allowed to cool very slowly. You do this by passing a torch flame over it slowly and just let it cool, little by little. This will help prevent cracking. You do use nickel rod for welding cast.

Obviously this approach will require both a torch set up and a welder.

The prestolite rig JOJ was talking about will silver solder but I don't know about brazing.

I've used LP with oxygen in my cutting torch with special tips but have never tried brazing with a cutting tip and don't know if LP welding tips are available.

-- john (natlivent@pcpros.net), May 04, 2002.

Doreen, DEAR, careful with that "typical male" bit, ok? What's the opposite of a misogynist? Anyway?

-- joj (joj@home.org), May 05, 2002.

All right Joe, you are right- sorry, it wasn't typical, it was crude...How 'bout I amend it to "he started acting like a dawg" and leave all you nice guys out of that lump sum generalization?

-- Doreen (bisquit@here.com), May 05, 2002.

My dog, Sofus, just growled at you...

-- joj (joj@home.org), May 05, 2002.

I just wanted to throw something out - it might not help you with welding cast iron, but it might spark off a discussion about "homebrewing" an arc welder.

Anyhow, I am sure many of you know of (or may have heard about) building an "on the road" battery box style welder, for off-road based welding. I am also sure you have ran across arc welders that used larger AC DELCO alternators coupled with gas engines for welding. A few of you may have even seen welders made from recycled microwave transformers.

However, one design that I recently came across I have not seen anywhere else, and I wonder if it is because it doesn't work, is dangerous, or has simply "faded" from memory...

The best I can figure, it would be considered a "resistive ballast" arc welder.

I ran across it in an article I have in an old "How-to Electronics" or such magazine from the 1940's or 50's. Basically, it consisted of one of the old style "conical" heaters screwed into a ceramic lamp base, with one side of an AC plug wired to one side, the other side of the AC plug went to the "ground", and the other side of the lamp base went to the "stinger". The stinger was made from a hair curling iron, and the whole contraption (minus the ground and stinger lines, of course) was placed into a vented metal enclosure. I think there was probably a switch included as well.

Essentially, you plugged it into normal 110 VAC, and you couldn't blow a fuse/breaker, because the heater would simply heat up as usual, until it was unplugged, or the circuit was broken in whatever way. Now, of course, you only got 15-20 amps worth of welding power, but it would probably be useful for lightweight tack welding jobs. You were supposed to use very small rod with it.

This kind of a project might be a great father/son style or similar project. It would even make a good "tinkering" weekend project. But how would you build it nowadays?

I have only once recently managed to find a conical heater element, and that was on Ebay, and I got outbid. Anyhow, I don't think they are made anymore, or if they are, they are harder to find than hen's teeth, so to speak. So, what to do?

Well, there are tons of other heating elements that could be used, with care and caution - toasters and space heater elements come to mind. Many times these items can be had for cheap to free, from garage sales, thrift stores, and sometimes the trash. A little soldering and craftwork could easily yield a nice little welder.

I would mount the whole thing on a wood base, and wrap the element onto a surplus ceramic line insulator, or something similar (maybe mold a support from concrete/pyrolite/plaster - or a mixture?). Mount the element onto the center of the base. Take a large coffee can or similar and "upend" it onto the base. Cut a hole in the bottom of the can (which is now the "top" of the cover), and mount a 110 VAC muffin cooling fan and grill to keep the element under temp. Poke some holes in the base of the can (the edge next to the wooden base) to allow for the "draft".

Can anyone think of a variation on this style of "arc welder" that would allow for more current, but still remain relatively simple and easy to assemble (ie, doesn't require complex "control" electronics, SCRs, triacs, etc, nor does it require "specialty" transformers)?

-- Andrew L. Ayers (keeper63@cox.NOSPAM.net), May 30, 2002.