mast track fitting

[jim]

Having just removed a alloy mast track which was fitted with mild steel screws, the track had corroded badly and the screws were in the same condition. What type of screw should i use in the new alloy track to avoid corrosion problems in the future.

Does anybody know of a mast track supplier?

Has anybody used the stainless screws as advertised by screwfix, a lot cheaper than my chandlers and are they ok for marine use?
Thanks for any advice.
Jim

Jim

 

[Peterduck]

I find it staggering that people will use mild steel and brass screws on boats! You can get away with brass if the boat will never, ever, see salt water, and the fitting is brass or bronze. With aluminium, use 316 stainless steel or monel. Test these when you sare buying them with a magnet. If they are at all magnetic, you don't want them. 304 grade stainless will still corrode, and it is weakly magnetic. 316 grade is not. Monel is best , if you can get it, but it is like hen's teeth to buy. Go to the industrial quarter to buy your fastenings, and buy a box at a time. You will get 100 screws at the same price that you would pay for 10 at your chandler! You may not need 100 screws now, but I have been glad to have a box of screws of approximately the right size many times. If you are fastening to an alloy mast, use "Pop" rivets, either aluminium, monel or stainless steel. Whether you are fastening to a timber mast or an aluminium one, put a bedding compound between the mast and the track. This is to prevent salt [or even fresh] water from lodging between the two components and fostering corrosion.
Peter.

 

[dickh]

I agree with all peterduck has said re monel etc. I always use Monel pop rivets and get them from Anglia Stainless Tel No 01359 251414 - prices always much better than chanleries.
I have used SS screws from Screwfix, they are A2 grade(not as good as A4) and have found them to OK - much cheaper than a chandlery. The only problem is that they are Pozidriv heads and not a screwdriver slot, so you need a good driver. If you are going to use them permantly and never remove once in, they are OK, but they don't stand a lot of removing amd reinserting as the recess gets badly worn.

 

[ccscott49]

Is the mast aluminium? if so use monel, not stainless, they will corrode. If its a wooden mast, you cannot beat bronze! They will not corrode the aluminium or themselves, available from anglia stainless steel.

 

[Plum]

Stainless steel screws into anodised aluminium track would be a good solution. You will get minor corrosion of the track around the heads some form of goo or varnish on the screws will help to seal and stop the moisture getting between the two. The worst that can happen is that you may have to renew the track again in 20 years, but at least the SS screws will come out cleanly. In my linited experience, even the cheepest stainless steel screws are OK (above the waterline, of course)

 

[jim]

Hi. Thanks for all the replies, i have been in touch with Anglia Stainless, I will be going for the Bronze screw option. The mast is wooden, its a pity the original track fitter did not have access to the advice available on this site, it would have saved me a lot of trouble.
Jim

Jim