Stainless vs Galvanised ?

[sarabande]

Wintertime project #5 is to make a 'universal' gantry for the stern to carry solar panels, assorted aerials, a stern seat, emergency nav lights, support for cockpit tent, kedge anchor and warp, handy hook for corkscrew, etc.

I have assorted lengths of stainless tubing in various diameters, and also some standard steel. No skills or kit for welding stainless, but some for ordinary steel.

99% of gantries I have looked at are in SS, but is there any reason that I cannot create one in ordinary steel, and have it either galvanised or powder-coated (there's a really good local chap) ?

What are the pros and cons of the two materials please ?

 

[Plum]

Wintertime project #5 is to make a 'universal' gantry for the stern to carry solar panels, assorted aerials, a stern seat, emergency nav lights, support for cockpit tent, kedge anchor and warp, handy hook for corkscrew, etc.

I have assorted lengths of stainless tubing in various diameters, and also some standard steel. No skills or kit for welding stainless, but some for ordinary steel.

99% of gantries I have looked at are in SS, but is there any reason that I cannot create one in ordinary steel, and have it either galvanised or powder-coated (there's a really good local chap) ?

What are the pros and cons of the two materials please ?

Probably comes down to asthetics. Will galvanised look right on your boat, particularly if most other metalwork is stainless. My boom gallows is galvanised and is still good after 25 years but on my old gaffer stainless would look wrong. I would certainly not use powder coating.

Www.solocoastalsailing.co.uk

 

[MM5AHO]

Being a galvanizer and powdercoater, I'd recommend 316 Stainless
Just saying "stainless might result in you getting some garde of stainless that's inferior for this application.

"Powdercoating" isn't a coating, in that it doesn't specify what is done, only how. Its an application method, not specifying which polymer is used. Lots of polymers can be applied using "powdercoating".
Galvanizing is a sacrificial coating, meaning it has a life expectancy. That is determined by the thickness of zinc and environment you put it in. It won't last "forever".

 

[PaulRainbow]

Wintertime project #5 is to make a 'universal' gantry for the stern to carry solar panels, assorted aerials, a stern seat, emergency nav lights, support for cockpit tent, kedge anchor and warp, handy hook for corkscrew, etc.

I have assorted lengths of stainless tubing in various diameters, and also some standard steel. No skills or kit for welding stainless, but some for ordinary steel.

99% of gantries I have looked at are in SS, but is there any reason that I cannot create one in ordinary steel, and have it either galvanised or powder-coated (there's a really good local chap) ?

What are the pros and cons of the two materials please ?

Unless your boat is an ugly beast, stainless is the way to go, IMO. Mine is 1" 316, unless you plan to fit heavy stuff like a windfarm, radar, davits etc, there is no need for scaffold pole sizes.

 

[TQA]

Welding stainless is not that difficult. You can do a reasonable job with a standard stick welder using a 308L rod.

It will not be as pretty as a pro TIG job but from 10 feet :eagerness::eagerness:

 

[DownWest]

Welding stainless is not that difficult. You can do a reasonable job with a standard stick welder using a 308L rod.

It will not be as pretty as a pro TIG job but from 10 feet :eagerness::eagerness:

Ditto, but use 316L rods, available in your local B&Q.
Or fab it all up with spot tacks and take it to a pro welder.

If you cost up the SS tube and then find out the minimum charge at your galvanizers, prob not a lot of difference.
Hint: If you do stick it with SS rods, mind the slag, it flys off fast and is very hot..
If you have any experience with a stick (MMA) welder, SS is not difficult.

Just realised you have the SS tube. No brainer! Also, if you have a mig welder, that does quite well too, gas reccommended is Argon with 2% CO2, but I find 8% is OK. Same as I use for steel.

 

[superheat6k]

These people do a wide range of stainless steel fittings, and at reasonable prices.

www.seascrew.com

You might be able to fabricate everything cold ?

Or if you want stuff welded contact Roy - spottydog5 - he runs a welding supplies company. He will likely know a man who can.

 

[sarabande]

Thanks everyone for the encouragement, contacts, and tech advice.

I am heading down to the boat with some lengths of plastic pipe to mock up a shape and see where my structural requirements (e.g. clearance height above someone standing in the cockpit, access to the stern cleats, etc) match up with the aesthetics.

Empiricism rules, OK

 

[pcatterall]

I assume that there is no detrimental effect in painting galvanised tube so the looks may not be such an issue?
Lots of my 316 ( stanchions especially) need regular polishing due to 'crevice corrosion staining'. I understand that highly polished 316 fares better but don't think that white ( say) painted davits would look bad on my boat.

 

[zoidberg]

These people do a wide range of stainless steel fittings, and at reasonable prices.

www.seascrew.com

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Good steer. Tracked 'em down to " http://www.sea-screw.co.uk/ "

 

[rogerthebodger]

Thanks everyone for the encouragement, contacts, and tech advice.

I am heading down to the boat with some lengths of plastic pipe to mock up a shape and see where my structural requirements (e.g. clearance height above someone standing in the cockpit, access to the stern cleats, etc) match up with the aesthetics.

Empiricism rules, OK

Thats how I designed mine.

Mine is made from 50mm dia 316 steel tube.

Find some one who can bend tube and design to minimise welding.

Tig is best but stick is also OK depends on the quality of finish of the raw welded joints. The was with stick is to weld and grind /polish back.


Bonk forget proper bracing otherwise the gantry could shake itself to bits is and seaway.

 

[KAL]

Hi Sarabande. There is an excellent SS fabricator about 5 mins from me, so very accessible to you on the way to the boat. Have used them in the past, also, to weld aluminium. Very knowledgeable, quick and v reasonably priced work of the highest quality. Happy to pass on details if you email me.

KAL