1982 MR 180

MNhunter1

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I would personally stick with aluminum rivets. Stainless for screws, aluminum for rivets. Solids preferred for anything structural, but if you don't have access to the tail end, then you're stuck with closed end blinds. Aluminum will avoid dissimilar metals and assumedly fill the hole better when set. Either way you go, the 3M5200 remains a must as well.
 

Sharpie223

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As a follow up since I quickly typed out my reply last night,

If it's a 3/16" hole and you need to buy fasteners anyway, I would highly recommend just getting a dimpled (2xxx series) aluminum solid rivet and finding an air hammer or someone who can set them. The closed end pop rivets end up the same cost each, stainless screws with nuts will as well. On my build I had stainless closed ends on hand already but I know I may have to change them if leaks form. Screws with serrated lock nuts should work well, but they also don't swell to fill the hole, so they rely on the sealant to fill the voids, the rivets are technically more water tight on their own. I did use stainless button heads where I was installing 1/4", as my air hammer couldn't get the rivets to buck, even at full power...

When I ran out of 5200, I used pc7 epoxy putty as sealant on the screws. It is a glass reinforced putty, plus some other stuff, very hard and reasonably impact resistant, incredibly difficult to remove from my mixing trays and tools. These were permanent installs though. I'm relying on the epoxy to help prevent loosening, as well as high torque. Just as another option. Don't use it for rivets though, it's a bit thick and may prevent proper tightening.
 
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redneck joe

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As a follow up since I quickly typed out my reply last night,

If it's a 3/16" hole and you need to buy fasteners anyway, I would highly recommend just getting a dimpled (2xxx series) aluminum solid rivet and finding an air hammer or someone who can set them. The closed end pop rivets end up the same cost each, stainless screws with nuts will as well. On my build I had stainless closed ends on hand already but I know I may have to change them if leaks form. Screws with serrated lock nuts should work well, but they also don't swell to fill the hole, so they rely on the sealant to fill the voids, the rivets are technically more water tight on their own. I did use stainless button heads where I was installing 1/4", as my air hammer couldn't get the rivets to buck, even at full power...

When I ran out of 5200, I used pc7 epoxy putty as sealant on the screws. It is a glass reinforced putty, plus some other stuff, very hard and reasonably impact resistant, incredibly difficult to remove from my mixing trays and tools. These were permanent installs though. I'm relying on the epoxy to help prevent loosening, as well as high torque. Just as another option. Don't use it for rivets though, it's a bit thick and may prevent proper tightening.
if i understanding (keep in mind you are talking masters level stuff to a third grader intellect) i need access to the inside which I do not. All will have to be completed from the outside.

I am fresh water only, medium use on pleasant waters and stored in the barn. Floor is maybe 5-10 years out. With my usage not very worried about dissimilar metals.
 

Sharpie223

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if i understanding (keep in mind you are talking masters level stuff to a third grader intellect) i need access to the inside which I do not. All will have to be completed from the outside.

I am fresh water only, medium use on pleasant waters and stored in the barn. Floor is maybe 5-10 years out. With my usage not very worried about dissimilar metals.
If outside access only for now, just find 18-8 closed end rivets and 5200 them
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Please make sure they are STAINLESS.

Not trying to be argumentative, just that when I researched these, I had zero confidence in aluminum blind rivets for anything structural, they are very weak, comparatively. The stainless were about the strength of solid hard aluminum rivets. The stainless, especially coated, shouldn't give you any real corrosion issues, especially if used in freshwater.

Otherwise, I wouldn't worry about a well sealed screw if properly torqued and sealed.
Stainless and aluminum should never be touching or you have galvanic corrosion. The rivets should be aluminum
 

redneck joe

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While the risk is minimal for me, i will stick with aluminum. Thanks for taking the third grade approach on this one. Same on electrical, not smart at all on that other than very very basic stuff. Other than that I'm good. Owned lots of boats in my day.
 

redneck joe

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Bad news if i havent shared yet is the kicker i bought seems to have no spark. It was fine when i picked it up in SC. Hoping easy fix that can come later.


Good news is i quadruple measured for a lopro 12 gallon fuel take which doubles the old school six and it fit perfectly with room to spare. Sometimes the dims you get online are pretty ambiguous. So with the boy running at WOT a good part of the time for about thirty miles, I'm hoping to be able to cruise about 18 mph for about 75.

Next up, beer holders!
 

MNhunter1

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Good news is i quadruple measured for a lopro 12 gallon fuel take which doubles the old school six and it fit perfectly with room to spare. Sometimes the dims you get online are pretty ambiguous.
Interested in the brand/model of the 12 gallon tank as I'm looking to replace my dual 6 gallons as well.
 

redneck joe

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Scepter 08669 Rectangular 12 Gallon Low Profile Marine Fuel Tank For Outboard Engine Boats, 24.5" x 18" x 11.5", Red​

 

redneck joe

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Thinking I want to raise the seat (and windshield) about 3-4 inches which will allow me to put in a shelf above the tank that would end up at about 7-8 inches tall. Perfect to put a couple life jackets in there rather than the bow space as I have other future plans for that area.

Long term when I do the floor will be a belly tank.
 

roscoe

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Good luck fitting a tank below deck.
Space below is too small.
I couldn’t find any tanks that would fit.
 

Sharpie223

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May 24, 2021
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I'm not sure the dimensional difference between my late 60s 18' hull and yours, but I found some low profile belly fuel tanks used on ebay that looked like they would work, though much larger capacity than I wanted. I decided instead that I will probably get a 15-20 gallon aluminum fuel cell instead, keep it under the splashwell, and I'm making under deck storage where I would have put a belly tank.
 

redneck joe

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Right, but how long is that? I just bought a mixed set but thinking maybe 3/8" ?
 

Sharpie223

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You'll have to figure out if the rivet is through the hull and a rib, hull rib and keel/strake, or hull and keel. I don't remember thicknesses off the top of my head, but for my late 60s boat, hull was about .09, ribs also I think. You may be able to find some 1980 literature that lists thicknesses. Or use the depth tool on a pair of calipers and use a flashlight to estimate when it's at the end of the inside layer.

All that said, my unconventional opinion is that the rivet won't do more than seal the hole, so even if it's short, but expands and holds tight, you should be fine...with sealer.
 
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