Reply
 
Thread Tools Search this Thread
 
Old 16 November 2014, 23:39   #1
Member
 
Country: New Zealand
Length: 3m +
Join Date: Nov 2014
Posts: 32
Alloy hull, which fixings??

Hi guys, currently arranging where things are going to live on my boat but can't figure what fixings will be best. Hull is alloy but I believe stainless bolts and rivets are stronger than alloy ones, but will having these stainless fittings promote electrolysis or other deterioration problems..
__________________

__________________
rusty McCaw is offline   Reply With Quote
Old 17 November 2014, 11:33   #2
Member
 
Country: UK - England
Town: Oakham
Boat name: Blue Wave
Make: XS
Length: 6m +
Engine: Optimax 115
Join Date: Apr 2007
Posts: 135
Electrolysis

Yes always best not to mix metals where ever possible with alloy hulls but the problem will not be that bad if using ss, the boat is not left afloat and rinsed off with fresh water after recovering. If it were me I would go and see your local yacht mast rigger, explain what you are doing and see if you could scrounge a handful of his rivets. With the bolts, if using ss, I would use nylon or similar washers / grommets and ensure there is no metal to metal contact. But I though you Kiwis had lots of experience with alloy boats so there must be an abundance of local advice and help. OhÖ.. and I assume it is a rib hull not sib with floor boards but you have posted in the sib section.

Jon
__________________

__________________
Jon.esp is offline   Reply With Quote
Old 17 November 2014, 12:14   #3
Member
 
Country: USA
Town: Seattle
Boat name: Water Dog
Make: Polaris
Length: 4m +
Engine: Yamaha 60hp
Join Date: Apr 2007
Posts: 1,152
316 stainless is standard. Then add zincs to address corrosion just as you would with any other boat. If in fresh/brackish water you might consider manganese anodes as zinc isn't sacrificial enough and different aluminum alloys might end up being preferentially corroded (e.g. in your engine or remote from the zinc).

Aluminum bolts are: 1) not really available 2) 1/3rd weaker and will need to be massive to compensate.
__________________
captnjack is offline   Reply With Quote
Old 18 November 2014, 02:44   #4
Member
 
Country: New Zealand
Length: 3m +
Join Date: Nov 2014
Posts: 32
Ended up using alloy rivets at this stage, thanx for you advice
__________________
rusty McCaw is offline   Reply With Quote
Old 18 November 2014, 11:40   #5
Member
 
Country: USA
Town: Oakland CA
Length: 3m +
Join Date: Feb 2005
Posts: 6,653
Keep an eye on those aluminum rivets. They tend to weaken with stress.

jky
__________________
jyasaki is offline   Reply With Quote
Old 20 November 2014, 09:25   #6
Member
 
Country: UK - England
Town: Oakham
Boat name: Blue Wave
Make: XS
Length: 6m +
Engine: Optimax 115
Join Date: Apr 2007
Posts: 135
Aluminium rivets

Agree with JKY. I think a rigger would have given you Monel ones and some Duralac or similar compound but perhaps thatís a bit OTT as we donít know what you are attaching to what. Hope it works out fine.

Jon
__________________
Jon.esp is offline   Reply With Quote
Old 20 November 2014, 13:00   #7
Member
 
Country: New Zealand
Length: 3m +
Join Date: Nov 2014
Posts: 32
Yea thanx guys, I used some high quality alloy rivets to fix a strap to support my fuel cell. Looking at shear strength I think I'm going to be fineClick image for larger version

Name:	ImageUploadedByRIB Net1416506435.139309.jpg
Views:	99
Size:	47.7 KB
ID:	100914
__________________
rusty McCaw is offline   Reply With Quote
Old 21 November 2014, 01:44   #8
Member
 
Country: USA
Town: Oakland CA
Length: 3m +
Join Date: Feb 2005
Posts: 6,653
Pretty much what I did on my SIB (a few times.) Eventually the rivets break the heads off, presumably from repeated stress. Hopefully you have better luck.

jky
__________________
jyasaki is offline   Reply With Quote
Old 21 November 2014, 02:34   #9
Member
 
Country: New Zealand
Length: 3m +
Join Date: Nov 2014
Posts: 32
If I have any issues I will go straight to stainless, I don't see this strap moving anytime soon tho.
__________________

__________________
rusty McCaw is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 14:55.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.