Looking for advice on aluminum casting

Home enthusiasts discuss their Foundry & Casting work.

Moderator: Harold_V

User avatar
ksierens
Posts: 51
Joined: Tue Jan 24, 2012 9:35 am
Location: Clinton Township, MI

Looking for advice on aluminum casting

Post by ksierens »

I have a chance to bay a part for one of my machines which is cast iron, but it broke in half. I checked with a welder, and he said it would be about $200 - $300 to braze, so I thought about having it cast in aluminum.

Can someone give me an idea of the cost to have a piece cast, and is there anyone you can suggest?

Image
User avatar
Metalman
Posts: 375
Joined: Wed Oct 12, 2005 8:38 am
Location: Connecticut

Re: Looking for advice on aluminum casting

Post by Metalman »

Where is the damage? Do you or your welder feel the braze job would not be a good repair?
My guess is having it cast in aluminum would far exceed the cost of $200-300.
Ernie F.
User avatar
ksierens
Posts: 51
Joined: Tue Jan 24, 2012 9:35 am
Location: Clinton Township, MI

Re: Looking for advice on aluminum casting

Post by ksierens »

You can see a crack in the picture along the right side where it is attached to the table bracket. It is actually broken in half there.

Maybe I should just pass on it and wait to see if I ever find one in good shape.

Thanks.
User avatar
Metalman
Posts: 375
Joined: Wed Oct 12, 2005 8:38 am
Location: Connecticut

Re: Looking for advice on aluminum casting

Post by Metalman »

OK I see it, the pic was small on my Iphone. Not familiar with that unit, yes a deal on a used one may be the way especially if you can find one soon and for not too many $$.
Ernie F.
hammermill
Posts: 2938
Joined: Sun Jun 27, 2010 10:43 pm
Location: pendleton or

Re: Looking for advice on aluminum casting

Post by hammermill »

given that it will need to be striped down, preheated, and slow cooled 200 may not be out of line, may be a job for nickel rod which has gone thru the roof.

make sure its cast, that gray color may be lighting,camera etc but it looks like al?
User avatar
ksierens
Posts: 51
Joined: Tue Jan 24, 2012 9:35 am
Location: Clinton Township, MI

Re: Looking for advice on aluminum casting

Post by ksierens »

I will have him double check. If it is aluminum, that would be much easier to fix.

Thanks Kurt
User avatar
ken572
Posts: 2600
Joined: Sun Mar 14, 2010 8:11 pm
Location: Mesa, Arizona. 85201-1517

Re: Looking for advice on aluminum casting

Post by ken572 »

ksierens, :D

$200.00 is a very fare price to pay, if it is

done properly. (Should look new when done.)

Don't forget, you could take a welding class at

your community college and use it as your project. :idea: :wink:

Ken. :)
One must remember.
The best learning experiences come
from working with the older Masters.
Ken.
User avatar
steamin10
Posts: 6712
Joined: Sun Jun 08, 2003 11:52 pm
Location: NW Indiana. Close to Lake Michigan S. tip

Re: Looking for advice on aluminum casting

Post by steamin10 »

IMHO, do not cast in aluminum. This was either a striking failure or a fail of the stops. Fix the cause first. This is a weld job, pure and simple. Not a lot of stress, but the setup is most important since we need to align shafting. We can get it close and still survive some drift from cooling.

I would: disassemble the drive parts and align the broken pieces. I believe it to be cast iron, so nickle rod is the most desirable repair. Some grades of cast iron are not very compatible with the bronze brazing rods available, the higher the carbon content, the less reliable the brazing repair. Bronze or phospher bronze and not brass rod. I would align and spot weld the perfectly fitted pieces, with tack welds, and then grind available areas, with a V-shaped relief, for a good overlay of nickle rod. You dont have to be a great welder for this, just ample skill to run a good bead. Nickle rod is actually nice to run, when you hit the heat range and flow onto the base material. A few minutes practice on some junk iron with the rod at 600-800 degrees will tell you all to the eye. 6-8 hundred is on the edge of black heat, but where you want to be for this kind of job. Higher heat into the bright red range is easier, but harder to control for the chill you need to set the bead. You will be welding on a heated hearth with a flame below to get it right, and stable, but easier than trying to weld cold metal. In this method, when you are done filling the grooves cut by your grinder, and they dont have to be big, just allowing some penetration fill, on the casting, just turn off your heating flame and cover it with dry sand, so it cools slowly. When cool, grind whatever is left for full 2 sided coverage, and repeat the heat and fill process, without getting silly and putting goose egg welds and chicken spatters every where. When cool the second time, everthing that looked broken should be covered with some weld, and grinding for finish, and looks should make your work look splendid without compromising the strength. Common Nickle rod is expnsive, but a pound is way overkill, it should be fresh to avoid moisture problems, and hydrogen embrittlement. I see just about 3 rods worth of work, plus practice. Prolly 8 rods total safely. A common problem, just take it in your teeth and do it.

Just an old guy, that has done it before.. Hammermill has probabaly done more than I. His opinion would be worthy here. But that is where I am. Good luck.
Big Dave, former Millwright, Electrician, Environmental conditioning, and back yard Fixxit guy. Now retired, persuing boats, trains, and broken relics.
We have enough youth, how about a fountain of Smart. My computer beat me at chess, but not kickboxing
It is not getting caught in the rain, its learning to dance in it. People saying good morning, should have to prove it.
redneckalbertan
Posts: 1274
Joined: Thu Nov 01, 2012 10:39 am
Location: South Central Alberta

Re: Looking for advice on aluminum casting

Post by redneckalbertan »

I have never had the luxury of being able to set a piece up with a constant source of heat on it like steaming 10 described above. I have always welded the cast iron cold. If you do it that way you want to do short little welds, probably no more than 1" long stop and pean weld. Another inch and another break to pean the weld. Cast iron is brittle and if you introduce too much heat into a very localized area it will tend to crack from the stress. The short welds help keep the heat input low and the peaning relieves built up stresses in the weld. If you do want to try the repair I would do as steamin10 describes I think that will result in a better result.

Regardless which way you repair it if you do it yourself I would use a nickle55 rod, as opposed to a nickle99. I have seen a lot of places up here that sell specialty rods like the 2 mentioned above in small quantities a half dozen or dozen rods in a package. Finding a supplier that will sell a small quantity opposed to a several pound box would also help keep costs low if you don't see yourself doing further cast iron welding.
User avatar
ksierens
Posts: 51
Joined: Tue Jan 24, 2012 9:35 am
Location: Clinton Township, MI

Re: Looking for advice on aluminum casting

Post by ksierens »

Well the good news is that the part is aluminum and not cast iron. Thanks to everyone for their comments!
User avatar
steamin10
Posts: 6712
Joined: Sun Jun 08, 2003 11:52 pm
Location: NW Indiana. Close to Lake Michigan S. tip

Re: Looking for advice on aluminum casting

Post by steamin10 »

There are some very good materials for gas welding aluminum castings. of course there is TIG that will work well if the AL is not pourous and oil soaked. Easier in some sense than cast iron, but not nearly as strong.

Good luck with your road.
Big Dave, former Millwright, Electrician, Environmental conditioning, and back yard Fixxit guy. Now retired, persuing boats, trains, and broken relics.
We have enough youth, how about a fountain of Smart. My computer beat me at chess, but not kickboxing
It is not getting caught in the rain, its learning to dance in it. People saying good morning, should have to prove it.
User avatar
ksierens
Posts: 51
Joined: Tue Jan 24, 2012 9:35 am
Location: Clinton Township, MI

Re: Looking for advice on aluminum casting

Post by ksierens »

Finally finished the power feed unit, here is some picture of it on my Benchmaster. Thanks everyone for the help!

Image

Image
Post Reply