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#11
posted to rec.boats.building
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bolt metal type in aluminum mast
On Sun, 27 May 2007 21:52:54 +0800, OldNick
wrote: On 22 May 2007 19:59:46 -0700, CB wrote stuff and I replied: Your geting replys Cb. Hows it goin'g I need to tap out a 1/4" hole in my mast to 5/16" 18 (no threads in there right now) and put a machine screw in there. I have some options in terms of metal types and there have been a number of discussions about corrosion and so on with SS in contact with aluminum and how really useless the isolating compounds are in a sal****er environment etc etc So what's the metal of choice? I'm seeing brass, SS, silicon bronze, zinc plated steel.. what's optimal for the aluminum (non-)interaction? These other discussions don't have a consistent conclusion. (And no rivets, this is a small job, I really do need the machine screw). This is a freshwater boat and has been for a long time. However I wouldn't rule it out of taking it down the east coast one day. Thanks for any comments, -CB In theory you want to use either aluminum or something very close to aluminum on the galvanic scale. So, in a perfect world you would purchase an aluminum bolt and use that. Unfortunately this is not a perfect world and an aluminum bolt is not very strong, wear resistant, or available (although they are made), so you go for the next solution and pick a metal close to aluminum on the galvanic scale. Say, Monel, for example. Locate a monel bolt and use that. Again, a bit uncommon but available. Or, you can do what nearly every maker of aluminum spars in the world does. Use stainless and insulate it as best you can. If it were my boat I would drill a hole and either tap it or screw in a sheetmetal screw, depending on the load to be placed on the "bolt", and then install the screw/bolt using something like 3M 5200 for a sealant/insulation. I have stainless bolts installed in both the boom and mast on a 40 ft. sloop, afloat in salt water, in the tropics, that have been there for ten years or more with no signs of corrosion to date. Bruce in Bangkok (brucepaigeatgmaildotcom) -- Posted via a free Usenet account from http://www.teranews.com |
#12
posted to rec.boats.building
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bolt metal type in aluminum mast
Ok so what I've done is tapped it out (yeah it's a fairly thin wall but this particular application doesn't have any kind of pulling load on it (it's a stopper in the boom/yoke downhaul slider)) and then put in an SS screw (probably 316 because my local chandlery is such a crap place), and I've insulated the connection point not with anti- seize but with a coating of 3M 4000 that I happened to have lying around. Time will tell.. I'm sure it's fine for the application. Thanks for everyone's comments, especially those regarding the aluminum riv-nuts. I will look into those for next time. Cheers, -CB On May 27, 10:19 am, Bruce wrote: On Sun, 27 May 2007 21:52:54 +0800, OldNick wrote: On 22 May 2007 19:59:46 -0700, CB wrote stuff and I replied: Your geting replys Cb. Hows it goin'g I need to tap out a 1/4" hole in my mast to 5/16" 18 (no threads in there right now) and put a machine screw in there. I have some options in terms of metal types and there have been a number of discussions about corrosion and so on with SS in contact with aluminum and how really useless the isolating compounds are in a sal****er environment etc etc So what's the metal of choice? I'm seeing brass, SS, silicon bronze, zinc plated steel.. what's optimal for the aluminum (non-)interaction? These other discussions don't have a consistent conclusion. (And no rivets, this is a small job, I really do need the machine screw). This is a freshwater boat and has been for a long time. However I wouldn't rule it out of taking it down the east coast one day. Thanks for any comments, -CB In theory you want to use either aluminum or something very close to aluminum on the galvanic scale. So, in a perfect world you would purchase an aluminum bolt and use that. Unfortunately this is not a perfect world and an aluminum bolt is not very strong, wear resistant, or available (although they are made), so you go for the next solution and pick a metal close to aluminum on the galvanic scale. Say, Monel, for example. Locate a monel bolt and use that. Again, a bit uncommon but available. Or, you can do what nearly every maker of aluminum spars in the world does. Use stainless and insulate it as best you can. If it were my boat I would drill a hole and either tap it or screw in a sheetmetal screw, depending on the load to be placed on the "bolt", and then install the screw/bolt using something like 3M 5200 for a sealant/insulation. I have stainless bolts installed in both the boom and mast on a 40 ft. sloop, afloat in salt water, in the tropics, that have been there for ten years or more with no signs of corrosion to date. Bruce in Bangkok (brucepaigeatgmaildotcom) -- Posted via a free Usenet account fromhttp://www.teranews.com |
#13
posted to rec.boats.building
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bolt metal type in aluminum mast
On 27 May 2007 10:55:18 -0700, CB wrote:
Time will tell.. I'm sure it's fine for the application. Thanks for everyone's comments, especially those regarding the aluminum riv-nuts. I will look into those for next time. Cheers, -CB Riv-nuts cost peanuts and go on with a pop rivet gun. But if you were paranoid about electrolytic corrosion, there is a species of rubber expanding nut with an internal metal threaded insert. That might suit some low strength applications too. Brian Whatcott Altus OK |
#14
posted to rec.boats.building
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bolt metal type in aluminum mast
On 27 May 2007 10:55:18 -0700, CB wrote:
Ok so what I've done is tapped it out (yeah it's a fairly thin wall but this particular application doesn't have any kind of pulling load on it (it's a stopper in the boom/yoke downhaul slider)) and then put in an SS screw (probably 316 because my local chandlery is such a crap place), and I've insulated the connection point not with anti- seize but with a coating of 3M 4000 that I happened to have lying around. Time will tell.. I'm sure it's fine for the application. Thanks for everyone's comments, especially those regarding the aluminum riv-nuts. I will look into those for next time. Cheers, -CB Basically that is exactly the way my mast was fitted out nearly 40 years ago when it was built, except that I have two SS screws holding in a very short section of the mast track. No problems to date :-) On May 27, 10:19 am, Bruce wrote: On Sun, 27 May 2007 21:52:54 +0800, OldNick wrote: On 22 May 2007 19:59:46 -0700, CB wrote stuff and I replied: Your geting replys Cb. Hows it goin'g I need to tap out a 1/4" hole in my mast to 5/16" 18 (no threads in there right now) and put a machine screw in there. I have some options in terms of metal types and there have been a number of discussions about corrosion and so on with SS in contact with aluminum and how really useless the isolating compounds are in a sal****er environment etc etc So what's the metal of choice? I'm seeing brass, SS, silicon bronze, zinc plated steel.. what's optimal for the aluminum (non-)interaction? These other discussions don't have a consistent conclusion. (And no rivets, this is a small job, I really do need the machine screw). This is a freshwater boat and has been for a long time. However I wouldn't rule it out of taking it down the east coast one day. Thanks for any comments, -CB In theory you want to use either aluminum or something very close to aluminum on the galvanic scale. So, in a perfect world you would purchase an aluminum bolt and use that. Unfortunately this is not a perfect world and an aluminum bolt is not very strong, wear resistant, or available (although they are made), so you go for the next solution and pick a metal close to aluminum on the galvanic scale. Say, Monel, for example. Locate a monel bolt and use that. Again, a bit uncommon but available. Or, you can do what nearly every maker of aluminum spars in the world does. Use stainless and insulate it as best you can. If it were my boat I would drill a hole and either tap it or screw in a sheetmetal screw, depending on the load to be placed on the "bolt", and then install the screw/bolt using something like 3M 5200 for a sealant/insulation. I have stainless bolts installed in both the boom and mast on a 40 ft. sloop, afloat in salt water, in the tropics, that have been there for ten years or more with no signs of corrosion to date. Bruce in Bangkok (brucepaigeatgmaildotcom) -- Posted via a free Usenet account fromhttp://www.teranews.com Bruce in Bangkok (brucepaigeatgmaildotcom) -- Posted via a free Usenet account from http://www.teranews.com |
#15
posted to rec.boats.building
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bolt metal type in aluminum mast
Brian Whatcott wrote:
Aluminum riv-nuts are easily obtained, easily fitted, and reasonably replaceable when the time comes. Screw a SS screw into a riv-nut Brian, do you have a link to a source for these riv-nuts? I can't seem to find them. |
#16
posted to rec.boats.building
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bolt metal type in aluminum mast
Dan "dhapp-at-wmis,net" wrote:
:Brian Whatcott wrote: : Aluminum riv-nuts are easily obtained, easily fitted, and reasonably : replaceable when the time comes. Screw a SS screw into a riv-nut :Brian, do you have a link to a source for these riv-nuts? I can't seem :to find them. Mcmaster-Carr sell them. www.mcmaster.com, look for "rivet nut" in the fastener section. |
#17
posted to rec.boats.building
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bolt metal type in aluminum mast
David Scheidt wrote:
Dan "dhapp-at-wmis,net" wrote: :Brian Whatcott wrote: : Aluminum riv-nuts are easily obtained, easily fitted, and reasonably : replaceable when the time comes. Screw a SS screw into a riv-nut :Brian, do you have a link to a source for these riv-nuts? I can't seem :to find them. Mcmaster-Carr sell them. www.mcmaster.com, look for "rivet nut" in the fastener section. THANK YOU! |
#18
posted to rec.boats.building
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bolt metal type in aluminum mast
On 27 May 2007 10:55:18 -0700, CB wrote stuff
and I replied: so are you actually listening to what you have asked about? Ok so what I've done is tapped it out (yeah it's a fairly thin wall but this particular application doesn't have any kind of pulling load on it (it's a stopper in the boom/yoke downhaul slider)) and then put in an SS screw (probably 316 because my local chandlery is such a crap place), and I've insulated the connection point not with anti- seize but with a coating of 3M 4000 that I happened to have lying around. Time will tell.. I'm sure it's fine for the application. Thanks for everyone's comments, especially those regarding the aluminum riv-nuts. I will look into those for next time. Cheers, -CB On May 27, 10:19 am, Bruce wrote: On Sun, 27 May 2007 21:52:54 +0800, OldNick wrote: On 22 May 2007 19:59:46 -0700, CB wrote stuff and I replied: Your geting replys Cb. Hows it goin'g I need to tap out a 1/4" hole in my mast to 5/16" 18 (no threads in there right now) and put a machine screw in there. I have some options in terms of metal types and there have been a number of discussions about corrosion and so on with SS in contact with aluminum and how really useless the isolating compounds are in a sal****er environment etc etc So what's the metal of choice? I'm seeing brass, SS, silicon bronze, zinc plated steel.. what's optimal for the aluminum (non-)interaction? These other discussions don't have a consistent conclusion. (And no rivets, this is a small job, I really do need the machine screw). This is a freshwater boat and has been for a long time. However I wouldn't rule it out of taking it down the east coast one day. Thanks for any comments, -CB In theory you want to use either aluminum or something very close to aluminum on the galvanic scale. So, in a perfect world you would purchase an aluminum bolt and use that. Unfortunately this is not a perfect world and an aluminum bolt is not very strong, wear resistant, or available (although they are made), so you go for the next solution and pick a metal close to aluminum on the galvanic scale. Say, Monel, for example. Locate a monel bolt and use that. Again, a bit uncommon but available. Or, you can do what nearly every maker of aluminum spars in the world does. Use stainless and insulate it as best you can. If it were my boat I would drill a hole and either tap it or screw in a sheetmetal screw, depending on the load to be placed on the "bolt", and then install the screw/bolt using something like 3M 5200 for a sealant/insulation. I have stainless bolts installed in both the boom and mast on a 40 ft. sloop, afloat in salt water, in the tropics, that have been there for ten years or more with no signs of corrosion to date. Bruce in Bangkok (brucepaigeatgmaildotcom) -- Posted via a free Usenet account fromhttp://www.teranews.com Human bevaviour: Bestiality with a brain |
#19
posted to rec.boats.building
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bolt metal type in aluminum mast
On May 28, 7:43 am, OldNick wrote:
On 27 May 2007 10:55:18 -0700, CB wrote stuff and I replied: so are you actually listening to what you have asked about? Ok so what I've done is tapped it out (yeah it's a fairly thin wall but this particular application doesn't have any kind of pulling load on it (it's a stopper in the boom/yoke downhaul slider)) and then put in an SS screw (probably 316 because my local chandlery is such a crap place), and I've insulated the connection point not with anti- seize but with a coating of 3M 4000 that I happened to have lying around. Time will tell.. I'm sure it's fine for the application. Thanks for everyone's comments, especially those regarding the aluminum riv-nuts. I will look into those for next time. Cheers, -CB On May 27, 10:19 am, Bruce wrote: On Sun, 27 May 2007 21:52:54 +0800, OldNick wrote: On 22 May 2007 19:59:46 -0700, CB wrote stuff and I replied: Your geting replys Cb. Hows it goin'g I need to tap out a 1/4" hole in my mast to 5/16" 18 (no threads in there right now) and put a machine screw in there. I have some options in terms of metal types and there have been a number of discussions about corrosion and so on with SS in contact with aluminum and how really useless the isolating compounds are in a sal****er environment etc etc So what's the metal of choice? I'm seeing brass, SS, silicon bronze, zinc plated steel.. what's optimal for the aluminum (non-)interaction? These other discussions don't have a consistent conclusion. (And no rivets, this is a small job, I really do need the machine screw). This is a freshwater boat and has been for a long time. However I wouldn't rule it out of taking it down the east coast one day. Thanks for any comments, -CB In theory you want to use either aluminum or something very close to aluminum on the galvanic scale. So, in a perfect world you would purchase an aluminum bolt and use that. Unfortunately this is not a perfect world and an aluminum bolt is not very strong, wear resistant, or available (although they are made), so you go for the next solution and pick a metal close to aluminum on the galvanic scale. Say, Monel, for example. Locate a monel bolt and use that. Again, a bit uncommon but available. Or, you can do what nearly every maker of aluminum spars in the world does. Use stainless and insulate it as best you can. If it were my boat I would drill a hole and either tap it or screw in a sheetmetal screw, depending on the load to be placed on the "bolt", and then install the screw/bolt using something like 3M 5200 for a sealant/insulation. I have stainless bolts installed in both the boom and mast on a 40 ft. sloop, afloat in salt water, in the tropics, that have been there for ten years or more with no signs of corrosion to date. Bruce in Bangkok (brucepaigeatgmaildotcom) -- Posted via a free Usenet account fromhttp://www.teranews.com Human bevaviour: Bestiality with a brain are you actually trying to troll me here? might want to work on your style a bit. -CB |
#20
posted to rec.boats.building
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bolt metal type in aluminum mast
On Sun, 27 May 2007 20:26:14 -0400, Dan "dhapp-at-wmis,net" wrote:
Brian Whatcott wrote: Aluminum riv-nuts are easily obtained, easily fitted, and reasonably replaceable when the time comes. Screw a SS screw into a riv-nut Brian, do you have a link to a source for these riv-nuts? I can't seem to find them. I googled "riv-nut" for 30,000 hits. I googled "riv-nut supplier" for 3000 hits. Here is one of them. It has a cross-section diagram to give you the idea http://www.cardinalcomponents.com/fasteners.htm Brian Whatcott Altus OK |
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