Mast pipe question

[The20poundhammer]

Guys which is stronger a 2" .250 wall 6061 aluminum mast pipe or a 2" .125 wall with a 1.75 with a 1.25 wall sleeved inside it.

 

[r carl]

How long?

 

[The20poundhammer]

I forgot to put that in there bout 8 feet long heavy antenna going on it 142 lbs

 

[r carl]

Between the two I would go with the aluminum.

 

[The20poundhammer]

Both aluminum what i am asking is a 2" .250 wall thickness or a 2 " .125 wall thickness with a 1.75" .125 wall thickness sleeved inside the 2" .125 which is the strongest.

 

[Blackcat630]

Well .125 + .125 = .250.. should be the same? I would probably just go with the 2" .250 wall. Easier and don't have to mess with 2 pipes.. . Jmo..

 

[The20poundhammer]

Well i can also get schedule 40 and schedule 80 in aluminum pipe with the same wall thickness

 

[Shadetree Mechanic]

I forgot to put that in there bout 8 feet long heavy antenna going on it 142 lbs

I can imagine myself with an 8 foot piece of 1/4 inch thick 2 inch diameter aluminum pipe. Stick it between two boulders and pull on the end with my 6'2" 250 pound self. I don't think I can bend it.

 

[Shadetree Mechanic]

I would think that the pipe inside the pipe for the same total thickness would be about the same. Unless the surface hardness would help it, then it would have twice the amount of surface.

 

[The20poundhammer]

I was thinking the same thing there. The only thing worries me is if we get another ice storm like squashed my quad. I think the Mosley will hold up to it but want to make sure so will the mast.

 

[Captain Kilowatt]

Both will have similar strengths however I would go with the single heavier piece. Easier to deal with and as the two pipe configuration flexes in the wind the two pieces will actually rub against each other unless they are cross bolted in a couple places.

 

[The20poundhammer]

Good point there CK if i did go with the sleeved deal i was going to put a couple bolts thru it. I also looked at 2" .125 steel tubing quite a bit more weight but i am sure stronger.

 

[r carl]

Between the two I would go with the aluminum.

I assumed the 2 pieces were steel. Go with the 1 piece. BTW 2 1/2 x 3/16 would be stronger yet.

 

[Captain Kilowatt]

BTW since you are only talking about 8 feet long either proposal is MORE than adequate and a lot of over-kill. It's not so much the weight that is on it as the wind loading. An eight-foot length is going to be near impossible to bend and I highly suspect that something else will fail before the mast does.