I have no idea what Sch 10 stainless is like, but I used to see a lot of frames made out of 1/2" Thinwall EMT. I'm sure it was marginal at best, but probably adequate or it would not have been so common.

 

most frames built with conduit use 1" emt, 1/2"would bend or break. Stainlss steel ? sounds very spendy

 

I've built nine frames with locally-available and cheap chainlink toprail galvanized steel tubing, 1' IPS, 1.315" OD, with fittings from Hollaender SpeedRail or Diamond Aluminum. Per foot, it's lighter than sch. 40 aluminum, but not as stiff, and the thin walls can be crushed by setscrew fittings. So I plug the ends with 1-1/4" hardwood dowel set in epoxy.

This is a research cat built for the University of Wyoming:

I've been running these frames in class III and IV water for years with no material failures.

Also built an ultralight cat frame of 3/4"IPS galvanized steel pipe with sch. 80 aluminum siderails.

Details under More Games With Frames.

 

So help me understand something - Just what exactly would be the advantage of a stainless frame?

 

Does anyone know what the relationship between strength and weight is for stainless? I tend to think of the stuff as heavy and not particularly strong, but I'd like to be wrong here just so you can get your bling on.

 

Does anyone know what the relationship between strength and weight is for stainless? I tend to think of the stuff as heavy and not particularly strong, but I'd like to be wrong here just so you can get your bling on.

.109 wall stainless steel is 2.085 per foot where AL is .721
.145 wall stainless steel is 2.718 per foot where AL is .940

Both above are 1-1/2 pipe just different wall thickness

 

The weight of steel and stainless steel are about the same. The differances between aluminum and stainless are many. To often only tensile strength and weight are considered. As an example Aluminum is one third the weight of staniless but is only one third as rigid. Yeild , fatigue, impact strenghts should also be consideredas well as diameter and wall thickness. Bottom line, stainless will make a great frame if the right size pipe or tube is used. One down side is that is is hard to drill and machine. It may weigh more but it will be strong.

 

Stainless weighs 2.9 times that of aluminum and coincidently 2.8 times stiffer by the mod of elasticity. Try 1.5" o.d. 16Ga to 20Ga Tube. You can get a seamed ornamental grade used for railings for a reasonable price. Cope and healiarc the joints. Do not fusion weld because they will fatigue out.

 

Stainless weighs 2.9 times that of aluminum and coincidently 2.8 times stiffer by the mod of elasticity. Try 1.5" o.d. 16Ga to 20Ga Tube. You can get a seamed ornamental grade used for railings for a reasonable price. Cope and healiarc the joints. Do not fusion weld because they will fatigue out.

He means TIG weld , heliarc is an old term coined from using helium as the shielding gas. Most the time argon is always used now. Although very few companies do TIG weld and just MIG them I havent seen any break. My boat is TIG Aluminum. I have never been a fan of fence post or handrail boats with speed fittings

 

Has anyone ever heard of using schedule 10 stainless steel pipe to make an oar frame. The wall thickness is .109 so it would cut down on weight, but I wonder if it is strong enough.

It would be plenty strong. Scratch that, it would be overkill strong.

 

This could be awesome. You could litereally have a kitchen sink welded into your frame