Stainless on Alloy

[MTpockets]

Hi boys,
Hoping to get some info here.
I am going to buy a bow roller with anchor lock on Monday for my tinnie and was wondering is stainlees steel fittings bolted to a Alloy boat a good idea? I was told once to seperate SS from alloy with a rubber gasket. I would also like to know what would be the best bolts to use to secure it with, galvanised or stainlees or another type?

I could ask a salesman at the joint I buy the roller from but would prefer to get a more experienced opinion from you guys.

cheers
Les

[Kerry]

If your going to have a stainless steel bow roller then the last thing you'd bolt it on with would be gal steel bolts. Stainless and alloy isn't perfect but no point using anything else if the piece is stainless anyway.

Just try and elimiante the contact as best as practical and that will generally be on the mounting surfaces etc, which has a lot more surface area than a couple of bolts. Also no point in bolting a nice solid SS bow roller to a sheet metal alloy deck, probably requires a backing piece (alloy, timber etc) under the deck.

But being an alloy boat then why not an alloy bow roller and weld it on, corrosion problems basically minimized.

Cheers, Kerry.

[MY-TopEnder]

Just be careful with the rubber gasket, i've read somewhere that some of compounds of rubber that are black have some effect on the alloy.. now i'm not sure how true this is but it could be legit.

[CHRIS_aka_GWH]

gasket cork - you get it from automotive shops. Separates metal surfaces, is a dense non-porous, manufactured cork so there is minimal connection via the seawater - the spring in it also helps keep nuts tight. Good also for seperating s/s u-clamps from aluminium bowrails etc. but sometimes insulating tape is easier.

double automotive trim tape - also from automotive shops could also be used for your bow roller application. Its available in a range of widths & thickensses

regardless of what you apply - if both surfaces are exposed & wet with seawater, they are in contact & interacting.

[MTpockets]

Nice advice and thanks. I have not actually found a gal version yet, but I am sure they are out there. All the ones I have seen so far on the net are SS.
I like the idea of the cork gasket as well as the backing board, didnt think of that
Awesome, problem solved (in my mind anyhow)
I am sure some of you know how damn frustrating it is with a screen, canopy and a front anchor and the non ability to retrieve an anchor through a split screen whilst a beer keg is strapped to ya waist. (dunno how that got there) The bow roller with anchor lock will answer all my problems.
Next problem........ convincing the boss that the government introduced a 3 day weekend..... and suggestions? lol
cheers
Les

[searaider]

My-Topender,
Your right , most black rubber will react with Aluminum .
There is actually carbon in the rubber that makes it black .
Carbon reacts with the Aluminum .
Natural gum rubber is the best , it's more a light red colour .

Peter
Searaider 2

[dnej]

I have an aluminium boat, and I had my bow roller made from aluminium. It consists of 3 rollers, mounted on a shaped channel, that pivits in the middle, and rolls the anchor off ,when tilted. Its held on to the boat, by a base wider than the shaped channel.The base is welded to the boat.
It was cheaper than the stainless over the counter job,and 10000 % better.
I can give you the builders name if this is any help. He is on the south side of Brisbane.
Hope this helps
David

[MTpockets]

That sounds very cool David. I will PM you and I will go that way I think. 1000 % is better than 100% in my book.
Cheers
Les

[jethro6641]

There is a product on the market that should be used on all stainless screws and bolts that are being used on aluminium. It creates a protective barrier between the two metals. It is a yellow paste and it is called Duralac Jointing Compound. This is what all of the alloy boat builders use when screwing stainless screws into aluminium. It acts as a loctite as well.

Hope this is of help.

Cheers,

Jamie

[MTpockets]

There is a product on the market that should be used on all stainless screws and bolts that are being used on aluminium. It creates a protective barrier between the two metals. It is a yellow paste and it is called Duralac Jointing Compound. This is what all of the alloy boat builders use when screwing stainless screws into aluminium. It acts as a loctite as well.

Hope this is of help.

Cheers,

Jamie

Thanks Jamie, Thats good info mate.
On the same subject, I had a clip break off the other day. It was popped on with aluminium pops, and looks to have corroded. What would be the best pops to use? The clip is stainlees and the rail is alloy.
cheers
Les

[jethro6641]

Hi Les,

I would use blind aluminium pop rivets and dip the rivet in Duralac and coat the underside of the clip with the duralc as well. I have just fitted out a 7mtr Plate alloy boat and I dipped every screw and rivet in duralac if there are two disimilar metals touching each other. That would be the reason why the rivet corroded in the first place. Where I used just aluminium rivets, I only used the blind waterproof ones and sealed those with just sikaflex.

Good luck mate. By the way to answer your question on Galvanised V's Stainless. I would not use anything but stainless on a boat.

Cheers,

Jamie

[Kerry]

Rivets, bolts, nuts, screws etc forget the marine places, forget the local hardware find a specialist who handles nuts & bolts and get the best there is for the job.

Alloy rivets can vary between the many different countries they are made and some of the countries are simply making cheap waste of time sh.. that might be allright for the chicken shed but not the best for a boat. Alloy ain't alloy in all cases.

Different grades of alloy/stainless are made for different purposes and your local hardware alloy rivet / SS nut and bolt simply might not be the most compatible alloy in a amrine environment.

There much to this corrosion type stuff especially with different metals. Just because a fitting is stainless doesn't mean that the alloy won't eat it away (size matters) as there's all sorts of other considerations in selecting the right type of fitting with the right type of fastener in as specific application.

Cheers, Kerry.

[Jack_Lives_Here]

DURALAC [smiley=2thumbsup.gif] [smiley=2thumbsup.gif]

[phewy]

Hey all. I know ali boats have some good points, but reading all this stuff makes me realise my decision to buy a Polycraft was justified! Anyway I think Kerrys spot on.

[Mr__Bean]

MT,

If you have the time, it also pays to drill the holes in the aluminium just a smidge bigger than you need, dob some paint in them and let that dry before screwing the assembly up with duralec as posted earlier.

- Bean