Attaching padeyes to aluminum arch tubes...

vizwhiz

vizwhiz

.
Aug 7, 2011
496
MacGregor 26S Lakeland, FL
So I have an arch on the back of my 26S made of 2" aluminum tube, and the idea is to use it to support all sorts of "stuff" on the back of the boat. There are a couple of lifting applications where I would like to attach padeyes to the aluminum tubes for swivel blocks or snatch blocks, and there may be "some" load when lifting things with them. (Can't define how much load...but reasonable weights should be assumed...raising the motor, raising the rudder, possibly holding a small dinghy, etc.)

Obviously, i want the padeye to face down, with the loop underneath the arch to hang stuff on. This means that the fasteners holding the padeyes will be under the arch and all the load will be pulling down on those fasteners, at least if I use a standard 2-hole padeye. So what kind of fasteners should I use? Rivets? Sheet metal screws? I don't feel comfortable with those, but didn't want to have to drill all the way through the tube with a 2-1/2" long bolt just to mount a padeye. Maybe I should just suck it up and do that? Any advice?

I'd like it to look clean at least, and even thought of using rope to lash them in place so it would also look nautical. But I didn't want to start there... Ideas?
 
justsomeguy

justsomeguy

.
Feb 20, 2011
8,060
Island Packet 35 Tucson, AZ/San Carlos, MX
Well, certainly not rivets, if the load is at 90 degrees to the face of the rivet. How thick is the wall of your arch?
Pictures and specs, man!
 
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Sumner

Sumner

.
Jan 31, 2009
5,254
Macgregor & Endeavour 26S and 37 Utah's Canyon Country
vizwhiz said:
....Obviously, i want the padeye to face down, with the loop underneath the arch to hang stuff on. This means that the fasteners holding the padeyes will be under the arch and all the load will be pulling down on those fasteners, at least if I use a standard 2-hole padeye. So what kind of fasteners should I use? Rivets? Sheet metal screws? I don't feel comfortable with those, but didn't want to have to drill all the way through the tube with a 2-1/2" long bolt just to mount a padeye. Maybe I should just suck it up and do that?....
Click to expand
I also wouldn't use the rivets or sheet metal screws. If you continue down this path I'd go with SS machine screws ....

http://www.albanycountyfasteners.com/Phillips-Truss-Head-18-8-Stainless-Steel-s/728.htm

... I get all my SS from the link above. Great prices and they ship fast. They have some in 316 and 18-8 stainless. I didn't see any long enough in 316 but have used a lot of 18-8 ss screws/bolts and they have held up great.

I also use this anti-seize...



https://www.amazon.com/Pro-Blend-530-1720-Anti-Seize-Compound/dp/B0127WLBMY

... on all of my SS fasteners and have never had a problem of taking them apart later. It goes on easy and works great. I buy it from Speedway Motors but see they are out of it so put in the amazon link above instead.

If the loads are substantial, such as a 10 HP outboard I think I'd want a mount that saddles over the top of the tubing to spread the load on the tubing but screws/bolts with washers on top are probably fine,

Sumner
===========================================================
1300 miles to The Bahamas and Back in the Mac...
Endeavour 37 Mods...
MacGregor 26-S Mods...
Mac Trips to Utah, Idaho, Canada, Florida, Bahamas
 
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Sumner

Sumner

.
Jan 31, 2009
5,254
Macgregor & Endeavour 26S and 37 Utah's Canyon Country
One thing to think about and your probably already have, is that if you drill holes in your arch and later want to move the location of the bracket, you now have a set of holes. If you made a simple "U" shaped bracket out of aluminum or SS with a bolt cross-wise at the bottom you could slide it to any place you wanted.

I've made a number like that over time and also lots of others...



http://purplesagetradingpost.com/sumner/endeavour-electrical/page-8.html

... for different situations,

Sumner
=============================================
1300 miles to The Bahamas and Back in the Mac...
Endeavour 37 Mods...
MacGregor 26-S Mods...
Mac Trips to Utah, Idaho, Canada, Florida, Bahamas
 
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justsomeguy

justsomeguy

.
Feb 20, 2011
8,060
Island Packet 35 Tucson, AZ/San Carlos, MX
Sumner said:
If you made a simple "U" shaped bracket out of aluminum or SS with a bolt cross-wise at the bottom you could slide it to any place you wanted.
Click to expand
Good idea. A strap out of aluminum would be easy to fab.
 
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vizwhiz

vizwhiz

.
Aug 7, 2011
496
MacGregor 26S Lakeland, FL
Thanks for all the good advice! The tubes are 2" aluminum... Bought a Junior Uni-arch from Fishonsports(dot)com. Very nice, was able to make it fit the back of the boat pretty well. I think it's going to look pretty good (but is still unfinished).

I figured the answers would be like this, but thought I would ask in case there were other options. I am putting a pulley system on one side to raise (tilt) the 9.9 extra long shaft, because it sits so far back on the transom that I have to stand in the motor well and hang over the motor to raise it (not power tilt). That's not good for the back, not to mention unsafe. So I'm hanging one of the blocks on the arch for the height, which is why I need a padeye or something to hang it from.

I thought about the strap idea (I like it) and thought it would be practical. I was just struggling a little with a couple issues. If I bring the strap all the way around, and use a bolt to generate the clamping force, then it's not as practical to also use that bolt to hang something from. If I leave the ears hanging down, then they have to have some width to support any load without tearing (being thin cross section of a strap). And the clips and toggles for blocks are relatively small, so I'm struggling with how to terminate a strap in a nice clean way that gives a thin but strong loop like a padeye has.

So I was thinking of the rope thing over a thin SS rod bent into the shape of an omega (a 'U' with legs sticking out on each side), with the legs about two inches long each. The two legs would run along the arch and I could strap those, or lash them with rope.
 
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justsomeguy

justsomeguy

.
Feb 20, 2011
8,060
Island Packet 35 Tucson, AZ/San Carlos, MX
vizwhiz said:
So I was thinking of the rope thing over a thin SS rod bent into the shape of an omega (a 'U' with legs sticking out on each side), with the legs about two inches long each. The two legs would run along the arch and I could strap those, or lash them with rope.
Click to expand
Or just use SS band clamps to attach your SS rod to the arch?
 
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vizwhiz

vizwhiz

.
Aug 7, 2011
496
MacGregor 26S Lakeland, FL
Or how about this? Aluminum strap, maybe 1/2" or 3/4" wide? Make it not long enough to go all the way around so that, when tightened and clamped, it leaves about 1/2" gap... Clamp bolt can be 1/4" dia SS bolt, and hanger bolt can be up to that size, maybe a #10 or something (which is 3/16" dia). Use a hanger bolt long enough to have the unthreaded shank across the gap, then cut the threads off to just fit the locking nut and not have a protrusion to catch stuff on.
 
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Sumner

Sumner

.
Jan 31, 2009
5,254
Macgregor & Endeavour 26S and 37 Utah's Canyon Country
I've made a number of straps like what follows...



The straps above and below were made to connect to only one side. For your situation bring both sides down and use the top hole to clamp with and the bottom as you mentioned to hang from.



I cut the round tube spacers about 1/16 of an inch shorter than the O.D. of the tubing the strap is going around. That way when you tighten the top bolt the strap tightens on the tubing but the strap is not deformed.

More on them here....

http://purplesagetradingpost.com/sumner/endeavour-electrical/page-9.html

... and in your case make both legs the same length.

Here is another set ....



... where I used 10-24 screws and the spacers are lengths of aluminum solid rod center drilled and cut about 1/16 the of an inch shorter than the diameter of the tubing, but it isn't critical. The long leg hasn't been drilled at this point, but will be depending on how they will attach to something. I've used a lot of different combinations to mount solar and ...



... other items to the boat. The one for the stern light has both legs the same length,

Sumner
=======================================================
1300 miles to The Bahamas and Back in the Mac...
Endeavour 37 Mods...
MacGregor 26-S Mods...
Mac Trips to Utah, Idaho, Canada, Florida, Bahamas
 
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jlp0217

jlp0217

.
Jun 27, 2014
117
Jeanneau Moorings International 50 Everett
Why not just use a soft shackle, a loop of rope around the the tupe? Quick and easy to set up, more, or remove, no rattles, and way stronger than any fastener.
 
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vizwhiz

vizwhiz

.
Aug 7, 2011
496
MacGregor 26S Lakeland, FL
Thanks for all the input. I'll have to sleep on this. Maybe put the whole rig together first and see what it looks like before I decide what to do. I don't really have something in my head already, but maybe one of the ideas will just click when I see the whole thing put together.

jlp0217 said:
Why not just use a soft shackle, a loop of rope around the the tupe? Quick and easy to set up, more, or remove, no rattles, and way stronger than any fastener.
Click to expand
Y'know, that's not a bad idea. And even if I don't leave it like that permanently, it would certainly work in the short-term. Thanks!
 
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