Aluminium Lower Unit Repair

[LA Weld]

Here is a little repair for my Aluminium Friends

The Customer brought this puppy into the shop for a quick repair

I get the fins from Mercury Performance out of Florida. You would think they would be finished better for what they charge but the unit is a little rough when received.

The Customer is a true crusader on abuse of a product to its full potential.

Welded with my Signature Series DX 300 (thanks to Kevin (KB FAB)for a great unit)

At least he gave me the lower unit minus the BOAT

A question for the Forum- I was told the Yamaha motors and the Hondas have a different Aluminium blend and cannot be welded. Something to do with a mixture of Magnesium in the Aluminum.
Anyone know the truth on this?

[Aerometalworker]

Here is a little repair for my Aluminium Friends

The Customer brought this puppy into the shop for a quick repair

I get the fins from Mercury Performance out of Florida. You would think they would be finished better for what they charge but the unit is a little rough when received.

The Customer is a true crusader on abuse of a product to its full potential.

Welded with my Signature Series DX 300 (thanks to Kevin (KB FAB)for a great unit)

At least he gave me the lower unit minus the BOAT

A question for the Forum- I was told the Yamaha motors and the Hondas have a different Aluminium blend and cannot be welded. Something to do with a mixture of Magnesium in the Aluminum.
Anyone know the truth on this?

Its not magnesium, its copper. And yes it can be welded. However I personally think any Yamaha or Honda should be scrapped anyway
If you want to weld on their castings use 4145 filler, preheat as you would normally for a cast material. Its nothing special, just cheap.

[aametalmaster]

The Merc's weld pretty good. I do about a dozen a year...Bob

[Craig in Denver]

Since alum x-fers heat so rapidly, is the prop shaft seal left in place? Is the gear grease drained? Even if the grease is drained, what keeps the remaining grease from coking? Or is there enough mass to keep the heat dissipated?

TIA, Craig

[LA Weld]

Since alum x-fers heat so rapidly, is the prop shaft seal left in place? Is the gear grease drained? Even if the grease is drained, what keeps the remaining grease from coking? Or is there enough mass to keep the heat dissipated?

TIA, Craig

Yes
No
NA
Yes
The front half of the weld is in a water port so no heat issues in this area.
The gear oil is Synthetic and the area that is exposed to heat is far enough away that a soaked rag is placed there to monitor and keep the temp in check. It never gets hot enough to steam, therfore less than 210 degrees.
Welding is done in 1" sections on opposite sides opposite directions to limit temp & any distortion potential, with time for cool down.

It is actually a fun repair as long as you are taking your time and have a good fit up. The bevel is a key component for the strength and if the customer does it again it will break on the edge.

[LA Weld]

The Merc's weld pretty good. I do about a dozen a year...Bob

Bob, how are the Evinrude/Johnson units?

Bob have you worked any Yamaha or Honda?

The next obstacle will be if the repair part is available.

[Aerometalworker]

The johnrude's should weld pretty easily. The alloy used in the Merc case is very forgiving for welding.

[aametalmaster]

I have a guy that brings me about 6 or 7 antique outboards a year but i forget what brand they are. They weld pretty good too. Most of those repairs are stress cracks and some rock damage...Bob

[Craig in Denver]

Thanks for the descriptive answers. How many amps, or 'full' with pedal? I ask because: someone asked me to repair an alum radiator tonight in class. The 'welded in' nipple had five lengthwise cracks. Since it was only for a petcock, he asked me to fit the ID with a nickel sized plug, welding the nipple shut. And since the cracks were all around the perimeter, he also asked that I run another bead around the nipple itself (over the original nipple weld, which was too smalll to call a weld, no ripples, 1/16" radius).

The 1/8" thick nickel sized plug went well at 150 amps. But the outer weld would have nothing to do with 150. I ended up at 250 amps and that took 'scary' long, full pedal, to puddle. There was obiviously plenty of alum there, but I've never used that much heat (home hobby guy with an aircooled Sync 250). At class: Syncrowave 250, watercooled, 1/8" green (that's what the class supplies) 3/32" 4043.

I could only run 3/8 to 1/2" beads because of the small diameter (maybe 1 1/8" OD). And I used a wet rag to draw the heat away, NOT on the weld, just under steam temps. Lots of starts / stops 'cause I'm afraid of the disasterous melt through.

All this to ask: how many amps for the DX 300 on this repair? Sorry about the hijack.

[LA Weld]

Craig, No HiJack

I was running 175Amps with pedal to get er done.