What Amps To Mig Weld 1/6 Alum. Jetski Block

[STEVE007]

pic of jetski ultra 150 block[called cases]

[STEVE007]

how do you upload pic,its saying it too big,thanks

[turboglenn]

Take the pics into microsoft paint or photoshop and resize them. I'm not sure what this board requires, but i know if my camera is on any more than 640 x 480 pixels or whatever that the files will be too large to upload and i use paint to shrink them.

[STEVE007]

jetski cases block

[FusionKing]

Child's play
Grind out that crack and bevel those edges and start circling inside the squares, alternating to avoid too much heat, until they are closed up. Then build up those ridges. I would fill the squares a bit more than stock for more beef. Flip it over and fill any low spots and grind it untill almost flush and then use cartridge rolls or flap wheels/disc for finish.
If you are really picky then do the same on the ouside and then play with the surface with a stone on the die grinder to get a finish very close to original
I find casting repair is way more prep and finish than welding.

[STEVE007]

Child's play
Grind out that crack and bevel those edges and start circling inside the squares, alternating to avoid too much heat, until they are closed up. Then build up those ridges. I would fill the squares a bit more than stock for more beef. Flip it over and fill any low spots and grind it untill almost flush and then use cartridge rolls or flap wheels/disc for finish.
If you are really picky then do the same on the ouside and then play with the surface with a stone on the die grinder to get a finish very close to original
I find casting repair is way more prep and finish than welding.

what amps should i use ,thanks for the info

[FusionKing]

what amps should i use ,thanks for the info

I do not have any exp with your machine, but you are playing with scrap first anyways, so set it at max IMO and then dial it back, while fiddling with the wire speed. Aluminum will only weld so cold, so you have a pretty small window of adjustment IMO
Did you get a manual with it?

[Craig in Denver]

If you decide to fully weld in the hole, remember this: when you're doing your practice pieces, weld on the edge, just like you'll be doing to fill the holes. If you practice on a solid piece, it will handle a LOT more heat than an edge. Then when you move to your case, the welder will be TOO hot.

I'd get some 3/16" or 1/4" thick alum and cut two pieces to fit the holes. Then you only have to weld around the perimeter. This will allow a larger margin of error (It won't blow a hole in the edge as easily).

[Vicegrip]

Make a tight fitting backing plate that the added filler metal can lay on. Use copper as the filler will not stick to it. Looks like the pump body and if so there will be less oil soaked into the metal. Clean, clean, clean and grind to fresh metal all the way around and clean well back from the edge inside and out. V cut the cracks then dril and fill a little hole at the end of each one

Good luck. I suspect that there will be a fair amount of test and tune

[FusionKing]

I'd get some 3/16" or 1/4" thick alum and cut two pieces to fit the holes. Then you only have to weld around the perimeter. This will allow a larger margin of error (It won't blow a hole in the edge as easily).

That sounds good but the inside of those cases are curved and clearances of moving parts is very close. You would be grinding almost every bit of those little pieces away because of that alone. It's all about the inside actually and you must weld those cracks anyway.
Then you have the issue of what material to make your "patches" out of in the first place because you are welding cast to billet then and may have weld dilution/compatibility issues as well. Not to mention the hassle of accurately clamping it to tack on.
The copper backing idea is much better IMO but after 30 years of this I simply just weld the dang thing and grind it perfect. You're only welding an inch or two at a time. That little wire is like a surgeons needle when used in capable hands!
A curved piece of steel would be even better IMO for a backer but you have to go inside and weld any ways to tie in all the welding and eliminate any stress areas before you grind it.
If I was gonna go with a "backer" I'd probably use it on the outside and weld from the inside first and then weld the square sections up a bit more.
You gotta get the toes to wet out over the pores or you will have a perforated line around your work when ground to size. Then that could start a leak/crack in some cases (pun intended)
If I was going to use a piece of stock I would weld the cracks first and then lay the new pieces on the outside and weld them in from the inside 100% then weld the outsides also. but I doubt I would attempt to make a "part"...BTDT but then YMMV