Looking for suggestions... Weld/redrilling

[mustangmike6996]

I have 2 aluminum boat parts that need to be rewelded and drilled. Looking for suggestions/recommendations on a machine shop/fab shop to handle the work.

 

[mustangmike6996]

Pics for reference.

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[wrath]

What is it?

Looks like cast. PITA. Can you change sizes and use a threaded insert (helicoil)?

 

[WhiteHawk]

Can you just put a nut on the backside of it?

-Geoff

 

[mustangmike6996]

What is it?

Looks like cast. PITA. Can you change sizes and use a threaded insert (helicoil)?

I have 2 that failed. One has a helicoil already. It sits below the waterline so I'm a bit apprehensive to do another helicoil. It gets torqued to 150 ft lbs.

Can you just put a nut on the backside of it?

-Geoff

No, I'm limited on modify it. It's the hinge pin bolt that holds the outdrive on the boat.

 

[mikesfastss]

I would make a template of it now to make sure you locate the holes after they fill it with weld and grind it down. Might save you a headache later.

 

[Siegel1719]

What is it?

Looks like cast. PITA. Can you change sizes and use a threaded insert (helicoil)?

Old cast aluminum parts are not easy to weld at all. Especially when your talking about filling a bore. It is near impossible to get a decent weld as it will be full of contaminent and likely voids from offgasing during the weld.

Probably two options for repair.

1. Easiest option if possible is to open up the companion part bore to the next largest bolt size. Then drill and re-tap this part. It appears to be a fine thread bolt and if it is I would re-tap with a course thread to ensure deeper thread engagement with the aluminum housing.

2. Bore out hole and press fit a threaded plug. You would then be able to weld the faces of the plug in fairly easily.

 

[camaromann]

How big are the holes? How thick is the part where the hole is? If you are local to warren area I can weld the entire hole shut. But I don’t have any machine capabilities to help with the drilling and tapping part.

 

[Detroit Gearbox]

Drill & tap them larger, make new pins.

 

[wrath]

Ah, hinge pins for a Bravo. I think Alphas take less torque. I was wondering why it looked familiar.

Anyway, they're in shear so the threads don't actually take much abuse (tension would be the worst for aluminum). A qualified welder can clean, heat, and fill it and then have someone machine the boss and thread it.

Usually what I see happen is someone will use the wrong thread sealer, the wrong anti-seize, or over-torque them... and the sacrificial anodes are missing.

 

[wrath]

And by the way, someone, somewhere, used to make a "kit" to repair these. West Marine? It's been decades. It's a heli-coil kit. Works fine but you need to have a true drillpress in order to not have bind later.

Someone used to make an insert you could weld in also. So you drill it really big and then TIG in the insert. I did this once, a really long time ago.