I see that Armstrong and Cabrinha are offering foils with titanium screws and inserts. I can find several sources for titanium screws but only in cross or hex head.
Is anybody else using titanium screws? Are they significantly more durable than stainless steel?
I have recently moved to 304 stainless steel Torx head screws. They're very nice to use and hopefully the head will be more wear resistant than the hex screws. It would be nice to get some 316 or titanium screws.
Would titanium screws be a solution to the corrosion problems with aluminium and stainless steel components?
What is their advantage over 304?, Weight and corrosion resistance, However, 316 performs suitably in kiteboarding applications. So the only real advantage is weight saving.
Will it be better for galvanic corrosion with aluminum? No. Titanium is higher up the galvanic chart than stainless steel leading to higher potential of galvanic corrosion with Aluminum.
In a saltwater environment you want to look for no more than 0.15 Voltage potential difference. Go bigger than that and you are into the possibility galvanic corrosion
I was going to ask about 316 torx screws as well. All I could find was 304. They are working fine so far.
My masts have 304 stainless barrel nut inserts. They have about 300 hours each on them. There's a little bit of surface corrosion on some of them but they work fine.
The real benefit to me of higher spec screws is the simple pleasure of using them. I do a full assembly every session and there is nothing nicer than the positive feel of the wrench in a new unworn socket. So far the torx wrench is fitting very securely into the head.
If I could spend $10-20 for a set of titanium or 316 screws that would never wear than that would be a lovely upgrade so what is already a wonderful foiling system.
Re: Titanium Screws
Posted: Sat Apr 27, 2019 7:38 am
by 3InletsWindsports
304 is food grade Stainless
316 is marine grade.
Loose the 304 ASAP
Button head Allen type in 316 are readily available at a decent bolts and fasteners industrial shop.
304 is food grade Stainless
316 is marine grade.
Loose the 304 ASAP
Button head Allen type in 316 are readily available at a decent bolts and fasteners industrial shop.
It's not that straight forward.
The difference between 316 and 304 is 2.5% molybdenum. Granted it does improve corrosion resistance. However corrosion potential is required changes dependant on temperature and salinity. Increase the temp and increase the chance of corrosion, increase the salinity and increase the chance of corrosion.
304 is good in average seawater application up to 20 Deg C. After there is a chance for corrosion. If you flush your bolts with fresh water afterward you reduce salinity and increase the temperature at which pitty corrosion thats place.
So... if your not in stupid hot climate and wash down your board/foil afterward then 304 will do you fine for several years.
Re: Titanium Screws
Posted: Mon May 13, 2019 1:29 am
by 3InletsWindsports
What appears to be described here is a Salt spray test.
Used to measure the adhesion of coatings by measuring how long it takes for rust to creep under a protective coating.
In the above it appears to compare a corrosive effect on various grades of stainless steel.
A salt spray test is applying a mist of salt spray at elevated temperature in a controlled booth.
The test does a good job of comparing different items by how the survive the salt spray test.
But not really an indication of real world conditions.
Nuts bolts rod tube etc. is readily available in both 304 and 316. May as well use 316.
Re: Titanium Screws
Posted: Mon May 13, 2019 3:14 am
by OzBungy
I have been using countersunk 316 hex head screws for years. The screws last fine but the hex head gets chewed out. Using a high quality wrench helps but that just delays the inevitable. It's only a minor nuisance. You can buy a bag of screws for a few dollars and keep them in the car. When the wrench starts slipping simply replace them. The hex T-wrench I use has a lot of flex so I spin the screws in then finish them off with a ratchet.
I recently switched to using 304 Torx tamper proof screws. So far the heads are a pleasure to use. The wrench gets a really positive lock on the head and it is more stiff than the hex wrench. I can spin the screws in and tighten them in one go. There is almost no chance of the Torx wrench slipping. There is a faint bloom of corrosion visible on the head. Nothing significant so far. As far as I can find there is no such thing as a 316 Torx head screw.
As I said in the original post, I hear of various brands offering titanium fittings. I can easily buy titanium hex head screws. They're cheap enough and readily available. As far as I can see there is no such thing as a titanium Torx head screw. I am hesitant to return to hex or phillips screws because they wear quite quickly.
I do a full assembly every session. The feel of the wrench in the screw and the ease of spinning the screws is a significant part of my enjoyment of foiling. It's the first and last thing I do every session. It's a trivial thing but if I can increase that enjoyment by spending a few dollars on the best quality hardware then I would do that.
