New Trimaran build

[ForSeTi]

Another video on my Youtube channel

https://www.youtube.com/watch?v=9wFz_1o0WyM

[ForSeTi]

I also updated my website

Project Interior Aft | ForSeTi

[Redreuben]

Forseti; I'd be very wary of the weight your adding, glass to bulkheads that don't need it, heavier ply, additional laminates inside ? I believe Kendrick construction is already robust compared to say Crowther tri's. Be careful you don't eat up the payload and kill the boat, light weight is its essence.

[ForSeTi]

Originally Posted by Redreuben

Forseti; I'd be very wary of the weight your adding, glass to bulkheads that don't need it, heavier ply, additional laminates inside ? I believe Kendrick construction is already robust compared to say Crowther tri's. Be careful you don't eat up the payload and kill the boat, light weight is its essence.

U are right.
@ present I have only added additional glass to the transom and bulkhead 10.
Bulkhead is 3 x 8mm instead of 2 x 9mm thick
I am using 8mm ply instead of 9mm ( because of availability and Ray said that would be OK) so I got some wiggle room.

[ForSeTi]

New video on my Youtube channel.

Work done on the double bulkheads that will wrap around the aluminium frames.
I also show my shortcut to get straight lines using a belt sander.

I hope U enjoy it. If u do, please give it a tumbs up...

https://www.youtube.com/watch?v=JqMUzXNjYDU

[ForSeTi]

New video on my Youtube channel.

Work done on bulkhead 18

I hope U enjoy it. If u do, please give it a tumbs up...

https://www.youtube.com/watch?v=Vw8O3AqNOzI

[ForSeTi]

This week I installed the plywood panel between the bulkhead and panel 18.
Guess it can be called the first part of the cockpit floor.

https://www.youtube.com/watch?v=3YhzkmMgicA

[ForSeTi]

As I dont have the knowledge or access to welding, and I want to do as much as possible by myself, I decided to use structural glue on the aluminum frames instead of welding them.
Smaller parts will be outsourced for welding, but @ the prices people ask for welding where I am @ (welding parts seems more expensive than the parts themselves) I choose the structural glue for the bigger parts.

https://www.youtube.com/watch?v=Lha6LXI4YGU

[Redreuben]

How expensive will the fix be when the glue fails ?


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[ForSeTi]

Originally Posted by Redreuben

How expensive will the fix be when the glue fails ?


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I imagine a lot
But then its been holding cars and planes together since decades +
encapsulated in plywood and fiberglass/epoxy

I've checked out some data and vids on the subject and the glue is thougher than the actual aluminum:
The glue has a peel strength of 87000 psi on every piece 100mm x 100mm.
It has a shear strength of 370000 psi, also on every piece 100 x 100

When I check the stats on 6082 aluminum the highest # I can find is 300MPa, which is 43000 psi. All other # are smaller

So unless my math is off no matter what force is put onto the frame, the aluminum would fail before the glue would.

Aging shouldnt be an issue either as the frame wont be exposed to the elements as it is encapsulated. @ least for the first couple of decades...

[Redreuben]

You've obviously done your homework. I'd be looking at stuff like its huge expansion coefficient as perhaps an issue.
I'm not a fan of aluminium in marine environments, if it were me I would have looked at substituting carbon.


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[ForSeTi]

Originally Posted by Redreuben

You've obviously done your homework. I'd be looking at stuff like its huge expansion coefficient as perhaps an issue.
I'm not a fan of aluminium in marine environments, if it were me I would have looked at substituting carbon.


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I'm following Ray's plans on that one
He probably checked everything and his plans use 6082-T6 aluminium

The future will tell...

[Fast Scarab]

Hi, plans show 6061 T6 alloy, I have checked 6082 and it looks to be ok but I would definitely weld together.
Ray Kendrick

[ForSeTi]

Originally Posted by Fast Scarab

Hi, plans show 6061 T6 alloy, I have checked 6082 and it looks to be ok but I would definitely weld together.
Ray Kendrick

Hi Ray

In Europe 6082-T6 is used instead of the 6061-T6 (kinda the European variant according to my supplier)

Welding isnt an option anymore, as they are glued @ present.
But as said before, the sheer and peel strength of the glue is a lot higher than the failure treshhold of the aluminium itself.
So I concluded, according to the specs, the aluminium would break/bend before the glue would fail.

Structural glue is used in aeroplanes and cars, both for aluminium and steel sheeting and depending on the kind U use u have upto a 40 year waranty.

I only use the glue on the frames, because they have a big surface to apply the glue onto, which gives the very high strength numbers.

The other parts will be welded, as they are known as "weak link constructions" because they have 90 degree connections.
(Upper and lower control arm, pivot attachments)

[Redreuben]

Ray;
Why aluminium ? Composite works for all your other boats ?
Such a dissimilar material seems incongruous ?



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