DaleH
FOUNDER of Classic Parker Forum
Galvanic Corrosion - One needs to be careful with aluminum in freshwater or salt, as aluminum is less noble than other metals. When two different metals touch or are pressed against each other, under tension or not, the less noble alloy will leech away electrolytes in deference to the electric potential of the more noble metal. Aluminum is down there on the noble metal chart, so it will leech away. You DO NOT want this to happen on an aluminum boat and it is made worse in a saltwater environment! See the aluminum being eaten away by the SS shaft and fasteners running through it?
In layman’s terms, if you use stainless steel (SS) fasteners on an aluminum boat, and DO NOT isolate any SS fastener from the aluminum, the aluminum will erode. See the picture below. There are a few methods one can successfully use to isolate any SS fastener used from the aluminum, so let’s take the case of a SS bolt put thru the hull sides, as that’s the typical installation example.
You can put thin 1/32” nylon washers under the heads of the bolt, as well as under the securing nylok nut, which should also bear against a smaller SS flat washer that’s right under the nut. To cover the ‘body’ of the length of the bolt that goes through the aluminum, I now use adhesive-lined heatshrink, but in the past, I’ve used electrical tape or suitable diameters of plastic tubing. I have also used e-tape or duct under the washers, trimmed to fit. Hey, it worked! Note you can also use special greases or products like Tef-Gel, reference (http://www.tef-gel.com/contain.php?param=tefgel_infor) to isolate the fastener from the structural aluminum.
Tools – I had to re-fasten the middle seat on this old hull, so I searched and searched for THE strongest rivets that I could insert, to be installed using hand tools, without resorting to an expensive couple-hundred dollar pneumatic tool. I finally found these in the fabulous, DIY’rs dream book – McMaster-Carr catalog.
Now to properly install these puppies, I needed a large rivet tool, but I found one of these large ‘wishbone’ ones on eBay for ~$40 delivered. I put new seat cleats (think 1/8” thick angled aluminum) against the hull and refastened the middle seat, and she’s as strong as new.
Plans - You're best to think out plans of what you want to do ahead of time. See my plans below. I had intended to remove the middle seat, add a locker against the port-side, but I finally came to that the design of this hull used the middle seat as a KEY structural member, to prevent the hull from buckling in on itself, so I kept it as is.
Costs to date:__________
* Costs from Part 1, $250
* (50) high-strength rivets $25 with shipping
* ¼” adhesive-lined heatshrink from www.bestboatwire.com $4
* ¼” nylon washers, McMaster-Carr $4
* Heavy-duty hand-rivet tool $40
Total to date ~$323
Oh yeah, through all of the boat trading I do, I got that trailer for $0. So far, there’s a rebuilt 16' hull and trailer for < $350? Sweet!
In layman’s terms, if you use stainless steel (SS) fasteners on an aluminum boat, and DO NOT isolate any SS fastener from the aluminum, the aluminum will erode. See the picture below. There are a few methods one can successfully use to isolate any SS fastener used from the aluminum, so let’s take the case of a SS bolt put thru the hull sides, as that’s the typical installation example.
You can put thin 1/32” nylon washers under the heads of the bolt, as well as under the securing nylok nut, which should also bear against a smaller SS flat washer that’s right under the nut. To cover the ‘body’ of the length of the bolt that goes through the aluminum, I now use adhesive-lined heatshrink, but in the past, I’ve used electrical tape or suitable diameters of plastic tubing. I have also used e-tape or duct under the washers, trimmed to fit. Hey, it worked! Note you can also use special greases or products like Tef-Gel, reference (http://www.tef-gel.com/contain.php?param=tefgel_infor) to isolate the fastener from the structural aluminum.
Tools – I had to re-fasten the middle seat on this old hull, so I searched and searched for THE strongest rivets that I could insert, to be installed using hand tools, without resorting to an expensive couple-hundred dollar pneumatic tool. I finally found these in the fabulous, DIY’rs dream book – McMaster-Carr catalog.
Now to properly install these puppies, I needed a large rivet tool, but I found one of these large ‘wishbone’ ones on eBay for ~$40 delivered. I put new seat cleats (think 1/8” thick angled aluminum) against the hull and refastened the middle seat, and she’s as strong as new.
Plans - You're best to think out plans of what you want to do ahead of time. See my plans below. I had intended to remove the middle seat, add a locker against the port-side, but I finally came to that the design of this hull used the middle seat as a KEY structural member, to prevent the hull from buckling in on itself, so I kept it as is.
Costs to date:__________
* Costs from Part 1, $250
* (50) high-strength rivets $25 with shipping
* ¼” adhesive-lined heatshrink from www.bestboatwire.com $4
* ¼” nylon washers, McMaster-Carr $4
* Heavy-duty hand-rivet tool $40
Total to date ~$323
Oh yeah, through all of the boat trading I do, I got that trailer for $0. So far, there’s a rebuilt 16' hull and trailer for < $350? Sweet!
