Need A Metallurgist's Advice

[JimS123]

Picked up a 1945 Neptune outboard at a garage sale. The PO bent the tabs on the bottom of the gas tank for whatever reason. The tabs are to support the motor when set down.

I have an idea how to bend them back straight again, but I thought I would see what y'all have to say. I'm afraid that it might just crack in two.

The pics below are the problem motor next to a restored one showing what it should look like.

 

[Jeff J]

I’m not a metallurgist but from experience I would say aluminum will break and steel might break. A good welder could repair them if they break.

 

[bajaman123]

Heat is your friend, but make sure that fuel tank is completely empty of gasoline if you do so and fill it up with water prior to using your heat wrench.

 

[Scott Danforth]

You will want to heat them to about 500-550 degrees to bend them. Go slow

I would recommend a heat putty to prevent the rest of the casting from getting warm

 

[JimS123]

You will want to heat them to about 500-550 degrees to bend them. Go slow

I would recommend a heat putty to prevent the rest of the casting from getting warm

Would a hand held propane torch be adequate?

The bars are aluminum.

 

[flashback]

Propane should work and a crescent wrench.

 

[Bugzilla46310]

Aluminum melts at 1200F. Don’t go nuts with the heat. Low and Slow!

 

[froggy1150]

Also aluminum will go from solid to vapor puddle without warning

 

[dingbat]

Most aluminum alloys are not readily bendable with heat or no heat due to its crystalline structure.

Since it’s bent, we know that it’s a 5XXX series aluminum which is highly mailable, ie readily bendable w/o heat

Aluminum is cold worked since heating aluminum is detrimental to corrosion resistance of the material.

 

[Scott Danforth]

5000 series aluminum is an extruded / rolled product vs a cast product. Most likely A356 or A380

The anneal point of the casting will be about 570F
A temp stick will be your friend when applying heat

 

[racerone]

Make something to slide over them as is?----Small rubber hose followed by bigger rubber hose as an example.

 

[Ifishmuskie2]

Get a piece of aluminum that you can practice on. It might tell you how much heat is needed.

 

[Scott Danforth]

Or use the IR thermometer that everyone that services their own boat should have