Step mast sit in

[Killick69]

The metal step that the mast sits in on my mark 3 (Night Cap), is badly corroded and I need some advice.
Water collects in all 4 hollows around the mast. There appears to be only one drain hole on starboard side.
Should there be more drain holes? It appears the mast is sitting on something. Could this be marine ply? Should it sit on marine ply? What is the foot of the mast made of (is the end of the mast finished off with aluminium or some other metal? Is the bottom end of the mast flat? I have cleared a lot of the muck out of the 4 hollows around the mast, but there is more in there and the drain hole is not allowing water to drain out. I have managed to drill one hole and will return with more well charged cordless drilling machines to drill holes into all 4 hollows. I have chipped and scraped away at the rust, but there is some I cant get to. Was thinking of using rust converter on the step, but not sure how it could affect the aluminium of the mast and any other metal used at the bottom end of the mast. The step appear grey....possibly galvansied metal. Anyone know what the step is made of? Are they all of the same metal? Anyone have any photos? I need to gather information before treating the rust (any in the process the mast will be affected) with rust converter, phosphoric acid, hydrochloic acid or coca cola. Does the metal mast step just sit on GRP on top of the cabin? Is the GRP continuous, any chance of water leaks? Should I run Silastic around the mast step? What does the metal step screw into (wood?). Does anyone know where I could get a second hand or new mast step (or reconditioned)? Any mast steps that allow lowering of the mast?
What is the best way to treat the mast step once cleaned....paint (what is best type) or zinc rich paint?
Internet search seems to indicate aluminium can tolerate phosphoic acid...but at what concentration...especially on an old and pitted mast.

[bearmcnally]

Hi Killick,

Don't PANIC take some happy snaps of your mast step and post them on the site and we can go from there!
I got some very good advice from a structural engineer once, and he said ," everything is fixable"


Regards Bear

PS had a look at the Night Cap photo's It looks like a galvanized" harbour bridge "step .Depending how badly it's rusted you may have to drop her stick to fix the problem properly because there's a good chance it's rusting between the underside of the mast step and the coachouse.

[Dolphin]

G'Day Mr Killeck,
As Bear says, take it easy, maaate.
Here is the arrangement of the mast step on Felicite. I don't know if its identical to what you have. Mine was filled with araldite in the centre section by someone who obviously had a great idea, probably at 3am on Sunday morning. I hope the sketch helps.

Top Hat MK 3 Mast step.JPG (7.36 KiB) Viewed 5609 times

There are 4 drain holes in each corner which you should have, you're right. THey may have been clogged with gunk or maybe even Aradite. WE only found that out when the rigging was redone by Paul Minter. The mast plug had to be chisseled out and cleaned up. It has about 2 to 3 mm of slop in the central box from memory. Its made of aluminium.

The weldmentment secton is indeed hot dipped galvanised. Mine is showing signs of rust in a small section. I plan to hit it with rust converter, maybe even POR 15 or so and seal it with sikaflex. I'll hit the bad parts of the weldment with Cold Gal and give it a few weeks to cure. I'll then paint it with Dulux weather shield or so to give it a better appearance.
If you really wanted to do a good job, you could take it off and get it hot dipped again. It costs about $90 for up to 50kg and at last count up here in Newcastle it was a 9 week wait. I don't think so.

I hope it helps. I'll put in the usual disclaimer that anything I say is in good faith and intended to be helpful but always double check the information you get. ie take it for what its worth. (Its free!)

Where are you located by the way?
Greg.

[Killick69]

Thanks for the info. That helps to exlain it and makes it a lot clearer. POR 15 is what I concluded might be the go. Just want to make sure it will not affect the aluminium of the mast in any way. Thinking of getting the starter pack, which has marine cleaner, metal ready and POR15. Will also get the spray pack, as one of the big problems I see is getting the POR 15 between the step and the mast, as there is no room for a paint brush. Moored at Mooney Mooney Creek.
Cheers, John

[storm petrel]

Best fix is to replace the hot dipped, mild steel 'harbour bridge' with an aluminium or stainless steel copy(either should last for the life of the yacht). I have seen Tophats with both these set ups and with replaced galvanized steel mast steps.

While you are saving up, a bit of a clean up - a dash of rust converter and some anti-rust zinc paint followed by a couple of coats of epoxy paint will hold the rust at bay for 6-12 months anyway. I found this method just as successful as Por-15 (Which is really only effective if you can get it all back to clean metal).

I have a couple of drain holes in the mast step, but both were blocked with paint when I got Storm Petrel and water used to sit in the mast step.The mast step has consequently developed some pretty serious rust but I have got by for the last three years by treating it every 8-12 months(only a couple of hours work). When I get the mast out next (planning this for 2014 or 2015 if I still have the boat) I will have the mast step replaced, probably with an aluminium one.

I think you can still get galvanised Tophat mast steps from the original firm that supplied Formit Fibreglass (who built the M11 and Mk111 Tophats) with mast steps up here on the Central Coast. From memory they are about $600 and the details are on a previous post on the site.

I agree with the others, don't worry too much about it, it is probably not as serious a problem as you think.

Cheers,
Mark

[Denis Smith]

MIJ"A has the same arrangement as displayed by Greg.
I lifted the Mast in 2007 (at Fenwicks Marina - Brooklyn) and replaced all the rigging.
If you lift the Mast, clean out the centre of the Mast Plug, as this fills up with all sorts of crud and grime, there should be a drain hole in the side of the Plug to allow water that gets into the mast to drain away.
I chip away at any rust on the Mast Step every year, first hitting the rust spots with 'Fertan' and then a rust inhibiting paint.

BY the way...Riggers had a tradition when laying a Mast and rigging for the first time of putting a coin of that year under the Mast for good luck. When I lifted the Mast on Mij'a I found in the center of the Mast Plug a 1970 Captain Cook 50c piece still in it's display case, which gives me a good indication that she was launched in 1970, where the Hull Identification Number (HIN) indicates 1969.

I put the coin back.

Mij'a is around in Parsley Bay - Brooklyn. So far I've counted 11 Top Hats moored in the Bay. I guess we will bump into one another on the River sooner or later.

Fair Winds
Denis
MIJ"A

[Miker]

To quote Storm Petrel "I found this method just as successful as Por-15 (Which is really only effective if you can get it all back to clean metal)"

That's not the claim PPC make for POR 15. What they say is to remove all flaking rust, clean with metal ready and paint the POR15 over the rest. Then, if you need to, fill it with epoxy to take out imperfections and paint with a top coat, because the POR15 isn't UV stable.

The POR 15 goes hard by absorbing moisture, not by having solvents dry out of the mixture.

I put it on some mild steel fittings on my Harley 8 years ago, there is no sign of rust. IMO, if you want to keep rust at bay, POR15 is the ONLY way to go.

BTW, they also have different products for painting boats, self levelling two packs which look very good.

Disclaimer, I have no affiliation with Permanent Painted Coatings, just good results.

Michael.

[storm petrel]

Well I followed the POR 15 instruction to the letter on Storm Petrel's mast step, but 8 months later, the rust came through. Perhaps constant wetting with salt water had something to do with the failure?

[Shaun]

Gday,
Yes Mark, I believe the main prob on NC is that the water is retained in the mast step, right up to the top of it & only goes away when it evaporates, there is only one drain hole & it appeared to be blocked by the mast plug.
John, I reckon it needs the four holes to allow the water to get away, as shown in Greg's drawing( thought you would of jazzed up the drawing with one of those famous LM seagulls perched on it, Greg )
regards
Shaun

[Dolphin]

G'Day Shaun,
I've since found out that the area south of Lake Mac Yacht Club where I am is also known as "The Shags Toilet". 'Nuff said.
Maybe I could plant something in it!
Greg.