Exhaust tube under tray

[joelake]

Hey there folks!

I have begun cutting into and de foaming tray.

I plan on widening the tray a fair bit, but I did not really anticipate the exhaust tube being so prominent. I looked at lots of other build threads so I thought, but didn't notice this being such a problem..... As it sits now, the exhaust is about 2 inches to high and 1 inch to far central for my tray plans.

I would like to avoid having a custom piece made only for time constraints.....

Any tips or good ideas? I can't seem to see any real way around this.

 

[JFGJetski]

I have head of people using flexible alluminum tubbing(the stuff that has those ribs in it) but dont know how you would attach it and how water tight they are also have heard of just moving it down and two the side if your up for more fiber glass work

Sent from my SM-G960U using Tapatalk

 

[Quinc]

IF you plan on running a 701 or larger it would be worth upgrading it to 2.25" or 2.5". What ever the size is that comes in the RN hulls.

 

[joelake]

Oh, it's a RN. The tube is about 2.5 inch already....

 

[Quinc]

You could re-route the Exhaust by using a Side Exhaust Outlet in the forward half of the Hull and deleting the Transom Exhaust Pipe section thereby giving you the space to lower the Tray.

That will be annoying loud. When I did my SN i recut the exhaust hole in the engine bay to lower the tube. Rear exist can remain unchanged.

 

[Req]

Same. I used a SS 2.25 ID tube and it stays under the tray the whole way, I have a wide tray so I did not have the room to route it in the stock location.

 

[joelake]

Well just for anyone else that may or may not be in this position.

I have a reasonable steel Fab shop/skill set, I ended up using my tube bender to bend the aluminum tube down in the middle.

I re drilled the bulkhead thru hole lower to clear the tray just, and carbon over the old hole (hull has had carbon reinforcement at some stage prior to me)

Worked out very well, but sadly the exhaust tube being in poor condition developed a split in the centre of the bend. Not having the equipment to weld aluminum, I wrapped it in carbon instead, using the old seran wrap method, worked out nice.

I filled the tray up with water bottles (lids on!) And used a few bits of EXP foam to tighten it up, then I layed the EXP foam on top of the bottles to get a flat surface, used more foam the shape the sides up etc. After this I layed a 200gm piece of glass over the foam and used some epoxy fairing compound to flatten a couple of weird spots off.

After that I layed this from bottom to top on the tray floor:

200gsm cloth x4
600gsm chopped strand x1
450gsm biaxial x1
200gsm cloth x4
A couple of 450 gsm tapes through the middle for good measure.

Total weight floor 2850gsm. (100oz?) Plus a bit

I am hoping that this would be sufficient for the tray floor in an experienced persons opinion?

Seems pretty solid?