trailer crossmember

[jetblue319]

hello
i need to replace my forward galvanized crossmember (3x3x64) on my homemade (part shorelander) trailer. can i use an aluminium crossmember of the same dimensions? do i have to worry about dissimilar metal corrosion? my 86 steplift is on it now.
jetblue

 

[garagenc]

No you would need to increase the thickness or overall size of the aluminum cross member. Aluminum is not as strong as steel when both materials are the same thickness and size.

Notice how large the beams are on a aluminum boat trailer compared to yours and that will give you a visual difference.

If you use aluminum to steel then use 3m black electrical tape to land (mate) the aluminum to the steel area or a galvanic corrosion will start and the steel & aluminum will start to pit and degrade.

 

[macojoe]

get steel and have it galvanized, Alum as sated above needs to be bigger Nd separated from the steel or its not lasting long.

 

[phatdaddy]

if galvanizing is not an option, i have had very good results painting bare steel with pettit trailercoat primer

http://pettitpaint.com/product.asp?id=96

 

[smokeonthewater]

why not just buy a galvanized crossmember?

 

[jetblue319]

well i was able to find a trailer store that will cut a galvanized "V" crossmember to size of old crossmember and weld the old "C" shape attachment to it. (ALL FOR ABOUT $140.00) The old attachment are in good shape. Now another question, i believe the welding will affect the galvanized treatment, in that area. i read somewhere about cold galvanized paint?? Anyone has any news on this
thanks for all the inputs
jet.

 

[Destroyer]

Yup... you can use that over the welds and it will work fine, or you can prime the bare welds with zinc chromate and paint them. The welds themselves are going to be your problem areas for rusting, since the deposited weld metal is not galvanized, so as long as you seal them from the air you'll be fine.

 

[jetblue319]

well i replaced the fwd cross member, bunk stiffner, had it weight at cty landfill (980 lbs) and register. next, as we're tapping the trailer for any signs of rust . we found some at the rt rear main frame, and at the fwd side of frame ( sorry no downloaded pic yet). well a trip to the trailer store, some 2x5 11 ga steel, a certified welder and my g/f's dad, and im back in business. pictures to come.

 

[nymack66]

Good job supporting the V....