Wheel Nuts

[jerson]

Is it possible to buy hot dip gal nuts for a boat trailer. The existing nuts are chromed & showing rust.

jerson.

[finga]

Just cover them inside and out with antiseize.
It's silver and the nuts won't rust on the studs as well.

Are they stepped nuts for alloy wheels or just tapered type nuts??

[STUIE63]

maybe take them to galvanizer and get them galled then run a tap through the threads
Stuie

[jerson]

There alloy wheels, there must be a reason gal nuts aren't available.

Jerson

[finga]

Yep there is a reason.
Zinc against the alloy would spell trouble. Dissimilar metals and activity series and all that caper.
Just spray them with inox or lanox or something like that so they don't rust up.

If they're stepped nuts then there's the tolerance factor as well which not be possible when they're galvanised.

[Spaniard_King]

mine are covered in grease... stops rust and keeps the light fingered people away :)

[wrxhoon]

You can buy S/S nuts if you wish, I'm not a fan because ater you do them up and undo them several times they strat to grab and stuff the thread.
I just use chrome captive nuts and antiseize on the theard , the outside of the nut will rust but no problem with the stud thread or the inside of the nut.

[Jasinex]

trojan sell a set of gal nuts and studs.. we used to sell them wen i worked at repco... they should still sell em

Jason

[Noelm]

just use plenty of good marine grease, it makes it messy if you need to remove a wheel, but still heaps better than trying to get rusted nuts off.

[FNQCairns]

As mentioned above cover them in grease, they will last near forever.

[Mr__Bean]

If you do install new galvanised nuts then do remember to keep tightening them for the first couple of significant trips.

Whilst they will initially tighten, the galvanising does extrude out under pressure and the nuts do work loose if you don't re-tighten.

- Darren

[White Pointer]

G'day,

Like the man said earlier - do not put galvanised nuts anywhere near your alloy wheels. On a boat trailer, after you have dunked them in salt water you have made a battery and that will spell lots of trouble.

Coat them with lanoline grease and loosen and retighten twice a year.

Regards,

White Pointer

[gofishin]

Yep there is a reason.
Zinc against the alloy would spell trouble. Dissimilar metals and activity series and all that caper...


G'day,

Like the man said earlier - do not put galvanised nuts anywhere near your alloy wheels. On a boat trailer, after you have dunked them in salt water you have made a battery and that will spell lots of trouble...Actually gents, quite the opposite, although it does confuse a lot of people!

To prove this we need to dig out the Chemistry book & look at the 'Table of Nobility' [and no, that's not a scene from Russell Crowe's Robin hood movie either..., ],'Noble Table', 'Corrosion Table'...it is called many names, here is one good example
http://www.dropanchorhere.com/fsetr/refgalvanic.html
ally and zinc (gal) are together on the table and are therefore very good together, and, much better than ally and stainless.
cheers

[White Pointer]

Actually gents, quite the opposite, although it does confuse a lot of people!

To prove this we need to dig out the Chemistry book & look at the 'Table of Nobility' [and no, that's not a scene from Russell Crowe's Robin hood movie either..., ],'Noble Table', 'Corrosion Table'...it is called many names, here is one good example
http://www.dropanchorhere.com/fsetr/refgalvanic.html
ally and zinc (gal) are together on the table and are therefore very good together, and, much better than ally and stainless.
cheers

G'day,

No hassles with the PTE but alloy wheels are not pure aluminium (Al) and galvanising is not pure Zinc (Zn).

But that is not the point. Don't invest in SS for wheel nuts and don't use gal wheel nuts. Use what you got and grease.

Regards,

White Pointer

[trueblue]

lots and lots of grease, all over them

looks like lots of grease, but grease looks better than rust

[finga]

Actually gents, quite the opposite, although it does confuse a lot of people!

To prove this we need to dig out the Chemistry book & look at the 'Table of Nobility' [and no, that's not a scene from Russell Crowe's Robin hood movie either..., ],'Noble Table', 'Corrosion Table'...it is called many names, here is one good example
http://www.dropanchorhere.com/fsetr/refgalvanic.html
ally and zinc (gal) are together on the table and are therefore very good together, and, much better than ally and stainless.
cheers
I'll use 316 stainless bolts, nuts and washers on my aluminium boat instead of galvanised gear thanks.
There's more at play when considering corrosion then the activity series of pure metals in a controlled environment.
Alloys (combination of different metals not just aluminium based alloys) have their own little rules which many people understand purely from experience and not from a text book.
ie galvanised fittings on an aluminium alloy boat react quite violently as compared to a good quality stainless.
Maybe that's why you never see galvanised fittings on new aluminium based alloy boats or even fibreglass boats

[TheRealAndy]

G'day,

No hassles with the PTE but alloy wheels are not pure aluminium (Al) and galvanising is not pure Zinc (Zn).

But that is not the point. Don't invest in SS for wheel nuts and don't use gal wheel nuts. Use what you got and grease.

Regards,

White Pointer

This is true, but the differences are minimal. The aluminium will be most likley alloyed with silicon, and the zinc may be alloyed with lead. If you buy nuts that are not gal, then there is a very likely chance they will be zinc plated anyway.

If you use chrome plated nuts, then they are more noble than aluminium, so the aluminium will corrode. In fact, chrome is probably worse than galvanised nuts if you want to be particular.

However, because your tralier is not immersed in the water all day everyday there will be minimal issues.

I have chrome nuts on my alloy wheels, and the chrome is coming off. I am to lazy to buy a new set so I just grease them up when I check my bearings.

[gofishin]

Gents, alloy wheels are made from aluminium and magnesium (for numerous reasons), and galvanizing is done in a bath of pure molten zinc, not lead. Over time there may be minute traces of other (low MP) molten metals & alloys etc within the bath, but of such low concentration it is not even worth worrying about – considering also there is a continual replenishment of pure zinc ingots to the process. If you are selecting materials purely on compatibility (and to protect the wheel), then gal(zinc) would be it, and as Andy has said, chrome nuts would be the worst.

Finga, the science of the Nobility Table is proven and ‘fact’ and has been used for maybe hundreds of years. Science cannot be refuted nor ignored, and if so we would still be living in caves using stone implements to feed ourselves. At times however, it is more practical using slightly less ‘compatible’ materials. I did not (and probably never will) advocate the use of gal fixings on an aluminium boat! Although stainless fixings will cause greater galvanic corrosion, they are more practical - at least you can unbolt the thing, and never have to worry about any constant maintenance (greasing/lubrication etc) required with gal fixings.

I have a nice US alloy bolted trailer that came with a combination of gal and s/s fixings. I would prefer that they were all s/s fixings, knowing that this would in fact be worse for my trailer, but I don’t want the hassle of the constant maintenance of gal fittings, and at least I know that in 10 yrs I could still unbolt the s/s fixing without any maintenance in between – hoping that my trailer has not corroded in the meantime. I have added more things and have used s/s fixings. My trailer has seen ~20 months use, and the only signs of (galvanic) corrosion of the aluminium are around stainless steel fixings (original), which I will obviously need to treat and insulate properly to reduce this problem.

FYI, 304 is actually better for aluminium than 316 because 304 is less noble and therefore closer to aluminium. Unless specifically noted otherwise, a lot s/s fixings sold at marine chandlers are 304, especially self tappers. The 304 fixings will probably tarnish more and look crappier than 316, but they will be better for the aluminium. Somehow though I think we will continue to disagree on this subject.:)
cheers

[finga]

Not going to argue about practicality over technicality. :)

Practicality usually wins.

[suzygs1000]

G'day,

No hassles with the PTE but alloy wheels are not pure aluminium (Al) and galvanising is not pure Zinc (Zn).

But that is not the point. Don't invest in SS for wheel nuts and don't use gal wheel nuts. Use what you got and grease.

Regards,

White Pointer

Have to agree with Gofishin.. I used all galvanised bolts and components on my aluminium trailer, and in three years, there are no signs of corrosion. I also did this based on the nobility table, which shows zinc and aluminium side by side, so I have to say it works a treat, and there are probably no two better metals to have side by side in salt water that galvanised iron and aluminium!

Dave.

[suzygs1000]

Further to the above, stainless and aluminium together, unless Duralac has been used, will start corroding in a very short time in a saltwater environment. This is from experience guys, and anyone who is not getting galvanic corrosion between stainless and aluminium must be using Duralac or similar.....

Dave.

[PWCDad]

This thread got me stressing about my new ALUMINIUM Mackay trailer with galvanised steel U shackles and under carriage. Also has gal steel roller angles in direct contact with the ally chassis.

I looked at the nobility table before purchase and went ahead with the order.

After delivery I called Mackay to discuss any potential galvanic action problem between the two metals interface.

Mackay technical asured me that there is not an issue with galvanic corrosion between the grade of ally they use and galvanised steel.

Mackay ally trailers have been around a long time now and are a proven item.

Even the Carlisle Hyd Brake reservoir is ally..

I hope to enjoy many years of corrosion free trailer with relatively easy maintenance.

Regards...

[TheRealAndy]

This thread got me stressing about my new ALUMINIUM Mackay trailer with galvanised steel U shackles and under carriage. Also has gal steel roller angles in direct contact with the ally chassis.

I looked at the nobility table before purchase and went ahead with the order.

After delivery I called Mackay to discuss any potential galvanic action problem between the two metals interface.

Mackay technical asured me that there is not an issue with galvanic corrosion between the grade of ally they use and galvanised steel.

Mackay ally trailers have been around a long time now and are a proven item.

Even the Carlisle Hyd Brake reservoir is ally..

I hope to enjoy many years of corrosion free trailer with relatively easy maintenance.

Regards...

Its pretty unlikly you will have any issues. In your situation, you dont have much choice but to use gal steel for the u bolts. Provided you hose it down and wash the salt water off you will never have any major problems.

[wrxhoon]

This thread got me stressing about my new ALUMINIUM Mackay trailer with galvanised steel U shackles and under carriage. Also has gal steel roller angles in direct contact with the ally chassis.

I looked at the nobility table before purchase and went ahead with the order.

After delivery I called Mackay to discuss any potential galvanic action problem between the two metals interface.

Mackay technical asured me that there is not an issue with galvanic corrosion between the grade of ally they use and galvanised steel.

Mackay ally trailers have been around a long time now and are a proven item.

Even the Carlisle Hyd Brake reservoir is ally..

I hope to enjoy many years of corrosion free trailer with relatively easy maintenance.

Regards...

I have ally trailer (USA built) , she is 5 years old now . All bolts are S/S but the U bolts were plated not hot dipped gal . After a couple of years the rear U bolts started to rust so I replaced them with S/S and i used a plastic hose where they come in to contact with alloy. I sliced the hose on the outside so it doesn't hold water in it . I undone all the bolts that hold the crossmembers and I used plastic washers under the S/S washers so the washer dosn't contact the ally. I used duralac on the bolts . To this day I havent had an issue with galvanic corrosion. The ally I beams are still shinney , the crossmembers have gone dull though but no corrosion at all.
I didn't bother doing anything with the draw bar and winchpost ( they are gal steel) where it bolts on the I beams because it doen't go in salt water .
The fact that your Hydrastar is alloy won't bother you because its not dunked in salt and its anodised as well.

[finga]

But back to the story...galvanised wheel nuts.
To get the tightening torques needed for wheel nuts they cannot depend on zinc to have the strength required so they run a tap through the galvanised (or hot dipped) nuts and you end up with bare steel again against the bare steel of the stud.
They kinda rust together as moisture gets into the gaps of the threads of the studs and nuts in a capillary type action.
A good coat of grease and capillary no longer works.

[bushbeachboy]

Grease has always worked well for me too. A bonus is that there has never been a problem changing tyres or removing the wheels for bearing work. Even when I have bought a new boat, I remove/grease/replace all the wheel nuts.

[TheRealAndy]

I think grease is better. If you must use antisieze, then make sure you use the right stuff for the metal in question. Antisieze is based on metals which can also cause corrosion. Copper based antiseize for carbon steel, and nickel based for stainless. I think you can also get non-metallic antiseize these days.