mcp 32 Posted October 26, 2019 Share Posted October 26, 2019 So I have acquired some stainless mast steps that are in great condition, that I want to install on my aluminium mast. I had planned to use Monel rivets [happy for other suggestions] and my questions was....should I use some tefgel on the rivets or something similar? My second and similar question....should I use some tefgel or similar on stainless nut and bots on the new anode I will be sticking on my shaft? Tips and alternative ideas are welcome. Quote Link to post Share on other sites
Cantab 341 Posted October 26, 2019 Share Posted October 26, 2019 Had very good results with Duralac, Stainless on Aluminium with Monel rivets, no sign of corrosion 15+ years. Never used tefgel but believe it suits better if you intend to remove fittings sometime. Always used to use Res-Q-Steel on nuts and bolts, amazing stuff, apparently they use Prolan these days. Quote Link to post Share on other sites
wheels 543 Posted October 26, 2019 Share Posted October 26, 2019 The more important point you have missed is between the step and the mast. You need an insulator of some kind. The best is to use a Polyurathane adhesive/sealant as a bedding compound and bond the step to the mast. Smear it on the fastening and that takes care of the fastening at the same time.If you happen to use a threaded fastener, use antiseize. I have tried many over the years and have slowly come back to the old tried and true proper antiseize products. That is not to say that Tefgel does not work. But aniseize is a complex product made for the specific purpose. 1 Quote Link to post Share on other sites
Steve Pope 243 Posted October 26, 2019 Share Posted October 26, 2019 Galvanised bolts and nuts are all you need and better than SS for attaching annodes. SS below the waterline is not a good idea. Sheep grease (raw lanoline) is ok for thread protection (doesn't allow the threads to seize) As Wheels says a thin membrane between the mast and the steps is the go. If using monel rivets you don't need to use protection on them as monel to all intents and purposes is inert, but if you do it may give you a little more piece of mind, belt and braces, so to speak. Quote Link to post Share on other sites
Island Time 1,211 Posted October 26, 2019 Share Posted October 26, 2019 I found rivets an issue with the design of my steps, so I drilled, tapped and SS machine screws, with duralac. Now, 10 yrs on, no sign of corrosion, and the screws can still be removed quite easily. Quote Link to post Share on other sites
splat 55 Posted October 26, 2019 Share Posted October 26, 2019 + 1 for duralac on any fastenings into aluminium Quote Link to post Share on other sites
mcp 32 Posted October 28, 2019 Author Share Posted October 28, 2019 You need an insulator of some kind. Good point. I like your polyurathane idea, cheers. Quote Link to post Share on other sites
idlerboat 116 Posted October 30, 2019 Share Posted October 30, 2019 The bottom line is to try to permanently electrically isolate the dissimilar metals. Many things mostly work...some for a long time some not so long. Duralac works, tefgel is less toxic. Machinary antisieze comes in many flavours. Common is copper or nickle based, but a whole raft of other stuff like...ally or graphite may be thrown in...The problem is...you are adding dissimilar metals !! Lanolin or clay based grease works for a time...If you drill and tap and use lanolin, then pull the fastener out and recoat every little while it works. You obviously cant do that if you chose rivets. I have seen plastic gaskets...rubber gaskets...epoxy... you name it...all with the white powder of death behind. ..and I have heard so many people say "well it cant have been done properly in the first place" or " I have never had a problem with it" .. But thats because we like to ignore basic truths like... when was the last time you took your rig off and de -riveted the whole lot for an inspection ? If at all possible use ally fittings on an ally mast. Stainless spreader bands and boom goose necks are a common and unnecessary problem. I have pulled these off rigs and found holes...These can just as easily be made from ally .Cast ally mast steps are very common and cause less problems. ( unless you are just putting a couple at the mast head or one at the tabernacle to make the main sheet to head board uncleating easier...) its a lot of SS fittings. I have seen massive pitting on masts all due to dissimilar metals. Do your self a favour, dont use them.. Quote Link to post Share on other sites
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