Stainless boat trailer axle? Bad idea?

[mmurray70]

Hey guys bit off topic but i have a small boat trailer with a rusty axle. Im looking for a long term replacement but not having much luck finding something that will hold up to saltwater over time. Its 3500lb axle, boat is only 2000 so not dealing with a whole lot of weight.

The old axle appears to be built out of 2" sch 40 steel pipe. How bad of an idea is it to make an axle with some 304/316 stainless pipe? Just weld a 1/2" or 3/4" flange on the end and use automotive style bolt on wheel bearings. I have the skills to tig weld it properly. Any thoughts? Stainless may be little weaker then mild steel, but at least it will never rot away and become weaker over time. Should i increase a size to be safe? Any issue with stainless against mating mild steel parts? Any other reason this is a bad idea?

Not terribly worried about liability here, please dont go there. Only used a few times a year for short distance and we are in very rural area.

 

[Bill D]

Will the bearings be ceramic or stainless? Do they make stainless brake hardware/ shoes/pads?
Bill D

 

[mmurray70]

Will the bearings be ceramic or stainless? Do they make stainless brake hardware/ shoes/pads?
Bill D

No brakes on this size trailer, its only 2000lb boat/engine/trailer. Thinking of bolt on bearings, the seals/bearings seem to last much longer then your standard trailer axles. I've used these bearings on some off road utility trailers before with great results. Just machine the mating flange and weld to piece of pipe or tubing and your good to go. Bearings are easy to change too

Have never tried it with stainless, or for an onroad application before.

 

[Gordon Heaton]

. . .Any issue with stainless against mating mild steel parts? . . .

The stainless will rust anywhere it is in contact with mild steel. This is not just 'rust stain' acquired from the mild steel either. You can prevent it by using a gasket, paint or powder-coat between mating surfaces.

 

[john.k]

I worked with a guy who made a completely stainless steel tandem axle trailer.....he was in scrap metal ,so didnt pay $10 /kg for the metal.............here,I can buy a boat trailer type solid axle /(Chinese no doubt) for $40 .....my experience of boat trailers,its the thin RHS/SHS that rusts away.....the cure is hot dip galvanizing......and ,in fact all the commercial boat trailers are hot dipped.

 

[moonlight machine]

Hey guys bit off topic but i have a small boat trailer with a rusty axle. Im looking for a long term replacement but not having much luck finding something that will hold up to saltwater over time. Its 3500lb axle, boat is only 2000 so not dealing with a whole lot of weight.

The old axle appears to be built out of 2" sch 40 steel pipe. How bad of an idea is it to make an axle with some 304/316 stainless pipe? Just weld a 1/2" or 3/4" flange on the end and use automotive style bolt on wheel bearings. I have the skills to tig weld it properly. Any thoughts? Stainless may be little weaker then mild steel, but at least it will never rot away and become weaker over time. Should i increase a size to be safe? Any issue with stainless against mating mild steel parts? Any other reason this is a bad idea?

Not terribly worried about liability here, please dont go there. Only used a few times a year for short distance and we are in very rural area.

Should be fine, I made the trailer hitch on my truck out of stainless, its fine.

 

[Scottl]

Might be a better idea to just use steel, coat it with something like moisture cure polyurethane or epoxy and borrow a trick from the boating world.

Bolt on a few sacrificial zinc anodes and change them as needed.

Also, fresh grease in the bearings every time you pull it from the water.

 

[GregSY]

I once planned to grease the axle bearings every time I pulled the boat out of the water, but I soon came to realize I was nowhere near that lonely.

Galvanizing is the answer....and really, do boat trailers rust that much anyway? I've had boats for 10 years that never had any trailer-rusting. They mostly sit high and dry....

 

[john.k]

Here you can buy special spring loaded hub outer grease caps.....pump up the cap with grease,and the spring hopefully keeps water out.....as to a stainless axle,it will be stronger than mild steel pipe,but not as strong as a solid heat treated 1040 axle.

 

[john.k]

Even the hot dip trailers fail eventually from use in salt water.....Ive repaired a lot of the A frame drawbars ,they seem to rust inside ,or maybe have the highest loading.

 

[Kingbob]

I live on the south coast of Louisiana, grew up on the water in my little oil field town where there is a machine shop on every corner. I've seen everything from stainless and aluminum trailers to Inconel trailer balls. That being said all you got to do is hose off your shit after you pull it out of the water.

 

[Scottl]

Here you can buy special spring loaded hub outer grease caps.....pump up the cap with grease,and the spring hopefully keeps water out.....as to a stainless axle,it will be stronger than mild steel pipe,but not as strong as a solid heat treated 1040 axle.

They've long been popular here as well, and that is what I meant when I said "fresh grease" except that for longest life fresh grease should be pumped in regularly, which only takes a few minutes with the fittings on the caps. A quick wipe of the grease that gets pushed out with a few blue paper towels and you are ready to hit the road. Even with the caps salt water can get in and contaminate the grease so regreasing should be part of the haul out ritual.

 

[dalmatiangirl61]

Do you guys realize he is not talking about turning spindles from SS, in fact his idea has NO spindles, he is just asking about a SS axle tube. I say build it, if it fails you got your answer, I'm betting it will be fine.

 

[john.k]

Not quite.....he is going to weld spindles into the SS tube.....this is how semi trailer axles are made ...a high tensile spindle is welded or swaged into a lower tensile tube....

 

[dalmatiangirl61]

Not quite.....he is going to weld spindles into the SS tube.....this is how semi trailer axles are made ...a high tensile spindle is welded or swaged into a lower tensile tube....

No, he is welding a SS flange to SS tube, then bolting on the hubs, see pic in post 3. No experience with that style hub, so cannot comment on those. There is no spindle, unless you count what is in the sealed hub.

 

[Garwood]

Not quite.....he is going to weld spindles into the SS tube.....this is how semi trailer axles are made ...a high tensile spindle is welded or swaged into a lower tensile tube....

No he is not.

He's going to use unit bearings bolted to flanges. No spindle whatsoever.

Sounds like a good idea to me.

 

[john.k]

Ah So ,as eggy would say.......car rear wheel bits.....seems like a lot more work than just a couple of spindles .

 

[reggie_obe]

The stainless will rust anywhere it is in contact with mild steel. This is not just 'rust stain' acquired from the mild steel either. You can prevent it by using a gasket, paint or powder-coat between mating surfaces.

SS axle tube, but what about the leaf springs? Just the next area for rust to consume.

 

[boslab]

When I went to college to study metallurgy we had an experiment to do, a stainless plate was cut ( 316L) 2x3x 18swg, ( could have been 3mm though), an elastic band was stretched round it and it was dumped in a beaker of saline, aka seawater, over a period of a few months the elastic band cut through the plate by crevice corrosion.
I must admit I was rather suprised, I’d spent my youth under the impression stainless steel was everything proof, wrong it got dissolved faster than a mild steel plate. Salt water is brutal around flanges, brackets bolts etc, the disruption of the oxide film forms a cell
Mark

 

[john.k]

I doubt the OP will leave his trailer submerged in seawater......marine grade stainless last near indefinitely in boat applications.Stainless steel propellers have some application in boats .