Cast Iron

[Markopolo]

Has anyone out there had any experience with Ni55 or Ni99
electrodes ? Would appreciate some "how to..." on them.
Now that i'm playing "weekend weldor" on my days off, the
neighbors are starting to come over with junk that needs
to be fixed :eek:

[james]

marko if you do use some ni55 or ni99 post and let us know how it went, had to do a little job myself on some cast iron brazed it but took forever. almost would have been better to have two guys one preheating with a rosebud and one guy brazing.
jim

[Franz]

Marko, if they are hauling that damn Mexican, Chinese or Indonesian cast porch furniture over to be welded DON'T TOUCH IT!! God doesn't have any idea of the composition of that cast, and it may well contain a few dead bodies. You have to be very careful when it comes to welding cast, especially when doing it for other people in the litigeous society today.

[Markopolo]

Thanks for the reply... From what I've read in the books,
brazing would probably be better for most cast iron repair.....
but one of the pending "projects" (from a kid down the street),
is a manifold...and I'm wondering about the operating temp.
of the manifold ? My other pending project is a park bench with
a broken leg.

[james]

marko i'll take the park bench you can have the manifold
jim

[Markopolo]

THANKS A HEAP ! :p

[Jerry]

In welding cast many things come to mind. First I grind out cracked area and or drill small hole at end of crack line if there's one. I then clean with wire wheel and I pre heat to around 400 degrees. Weld small stringers this is better then weaving but I've done this also. Peen area after welding, if welding an exhaust manifold heat to say 600 or 800 never clamp anything to cast to restrict it, it will come right back to where it was. A manifold will be the trickiest part to do but Iv'e done a dozen or more of these. After welding let part cool slowly such as placing it in sand or cover with old leather gloves.

Good luck

[Jerry]

If after removing weld slag weld has holes in it ( cast can be very porous) grind out area and weld again, you should then have a good weld. I have also welded on old harley bike cylinders replacing busted vent ribs with tig, tig welding works best in building up an area but not well on cracks where stress might be. Stick with nyrod 99 is what I have always used. I also welded on old machinery pcs. which welded great, some casts can not be welded also. There is some info on the Lincoln web site that will give you more info.

[Brainfarth]

I was looking into the ins and outs of welding cast and ran across this <a href="http://www.locknstitch.com/CastIronWelding.htm">link</a>
Lots of good stuff there.

-Brainfarth
<a href="http://www.brainfarth.com/bone">WWW.Brainfarth.Com</a>

[Markopolo]

OK boy's and girls.....here's an update on my practice with
Ni55 cast iron sticks: Tried to repair an old park bench....
Thought hard and long about brazing it, but the fact that the
break would need to be fixed as a "butt-joint", I decided that
welding might be better. I heard, (or read) somewhere that
brazed butt joints are a no-no.
Anyway...ni55....3/32"....90 amps d.c.+.....
It ALMOST works good !....Keep the rod pointed straight into the puddle.....no lead angle....and go S-L-O-W !
Even doing all this, I still wound up with a pretty high bead.
BUT IT WORKS ! :)

[Markopolo]

Forgot to mention that I got some serious porosity, this may be
from the fact that the metal is old & dirty....(YES...I DID WIRE BRUSH IT).....Guess I'll just grind the bead down and go
over it again ? :confused:

[Brainfarth]

I've tried to weld several things with several types of rods(from the kmart brand to the gold plated/jem encrusted types) and alot of them cracked out to a degree. Some of the welding I was trying do was in a corner of something like a reduction gearbox mount that took not only a tab off but the corner of the gearbox off(which happens alot). I would clean and clean, then burned the crud off till everything shined.. Preheated, welded(minimal porosity) then postheated and even heated plates up and layed them next to the welds to slow the process down. It still cracked in the cooldown(not the weld its self but where the weld meets the cast.) The answer was for me to fill the crack in, and fabricate a new mount around the same area. In a situation like that, if you can't afford the downtime and can't send it into a shop with an oven, it's the best way that (I) have found to fix the problem. It's not the prettiest way of doing things, but does work most of the time. If it's only a tab or just a straight piece of cast, it's no problem to weld it up or just mount some kind of backing plate and bolt it. Just be sure to wait till the part has cooled before bolting it or it will pull apart to a degree
Well... That's my two bits on the soapbox.

[DLN]

Hate to sould like the a fart here (but I am).....I have NEVER ( in 41 yrs)had a cast job come back that was I brazed....but have had to repair a lot of stuff other people tryed to do with nyrod....DL

[Brainfarth]

I must note "The answer was for me to fill the crack in" that I was refering to brazing. But I have to admit, after recently roaming the web, that I've had the wrong impression about brazing. I've always assumed(dont know from what) that brazing was an inferiror process compared to arc welding. That's why I would weld what I could and braze in the leaks and move on. From what I have learned, brazing goes from 65,000psi on up. I guess I've learned something tonight and will apply it asap.

[Franz]

Thebiggest problem with cast iron, particularly the crap that comes around seeking repair, is that we rarely know what the composition of the cast is. The damn Mexican and Chinese furniture seems like it's half sand. I for one, absolutely refuse to even attempt to weld, or braze cast furniture. People have just gottern too damn litigeous.

[Markopolo]

Franz...I know you warned me about doing repair on the neighbors cheapass cast iron, and I agree completely with you that this day and age has, indeed become too litigious !
But I tried it anyway :D My reasoning is that, if i'm hauled into
court because my weld fails....I'll look the judge square in the
eye and say: "I'm an undertaker, not a weldor"....I never professed to be a weldor...so, as the old saying goes:
"Let the buyer beware" !

[Franz]

Marko, your victims won't live long enough to get you into court, and given Floriodum's bankruptcy laws, what the hell chance do they have of collecting anything more than a lo mileage used pacemaker?

[Markopolo]

I really don't think there will be a problem. Cast Iron acts different when you weld (i've found out).
I used ni55, and the first pass was littered with porosity.
I broke out the die grinder, smoothed 'er down, and the second pass went down just as pretty as you please !

[Crithpy_Critter]

brainfarth,

two recommendations:

1. ditch the green background

2. your site wants to dump some pop-ups on me, sorry, but free surfer mk II blocks them all.

[Brainfarth]

The site is still coming together.. as for the popups: thats the price you pay for signing onto a free host
.