Transom work

Viper · 14 August 2006, 13:21

Hi ribnetters.

I am after a bit of advice from the knowledgeable.

I am changing my outboard for one with a longer leg, and need to fill in a cut out in the transom. The engine is also wider than the one being removed so raising the outboard solves having to widen the existing cut out.

I am proposing to infill the cut out with treated timber, which will be glassed in to match the transom. To strengthen this area I will then fix a 6mm stainless steel plate to the inside face of the transom.

PDF sketch attached.

The engine will then be clamped and bolted to the transom in the normal way.

Any advice, comments or better ways to achieve this would be most welcome.

codprawn · 14 August 2006, 13:37

What boat and what engine?

I would be tempted to get a transom jack or lifter. Saves messing about with the transom and maybe you won't nedd to get a longer shaft engine?

http://www.cook-mfg.com/

Great VFM and with the $ so weak you can get a bargain!!!

Viper · 14 August 2006, 15:48

Sorry Codders,

seems a little over kill, all that lifting kit will probably weigh more than the engine!

It is only a 40hp on a 5m rib.

Jelly · 14 August 2006, 16:29

Viper,
We have used a timber replacement section with large (3-5mm) S/Steel plates bolted through on inflatables, with hand stear 40hps on them.
This worked fine, the plates were about 4-5 inches bigger than the replacement section. We didn't glass it as it meant we could put a short shaft on the boat when the main engine was getting fixed.
good luck
Jelly

codprawn · 14 August 2006, 16:34

Quote:

Originally Posted by Viper

Sorry Codders,

seems a little over kill, all that lifting kit will probably weigh more than the engine!

It is only a 40hp on a 5m rib.

Ahh

bedajim · 14 August 2006, 16:44

Hi

My searider has a piece of treated hard wood bonded in and then a 5-6 mm aluminium plate folded to fit over the transom so it covers the inside and the outside with the engine bolts going trough it, I've not seen it move and no cracks

James

Erin · 14 August 2006, 21:13

I would have thought that given the stresses, and the fact the engine 'pushes' the boat along most of the time, that it may be better to have the reinforcing metal plate on the outside. IMHO

Powerboats · 14 August 2006, 22:44

I would say that, assuming you wish this modification to be permanent, that your plan is the most effective way of achieving your goal.

If I were doing it, as well as the stainless steel plate on the inside of the transom, I would fit a section of marine ply on the outside of the transom to absorb the "grips" on the inside of the transom mount of the engine.

Nos4r2 · 14 August 2006, 23:08

Quote:

Originally Posted by Erin

I would have thought that given the stresses, and the fact the engine 'pushes' the boat along most of the time, that it may be better to have the reinforcing metal plate on the outside. IMHO

I'd put the reinforcing both sides so it clamps the modified section.

Cookee · 15 August 2006, 10:11

Quote:

Originally Posted by codprawn

What boat and what engine?

I would be tempted to get a transom jack or lifter. Saves messing about with the transom and maybe you won't nedd to get a longer shaft engine?

http://www.cook-mfg.com/

Great VFM and with the $ so weak you can get a bargain!!!

I wouldn't recomend those lifters at all - what makes you suggest those codders? They are only for use on flat lakes in the US - the only ones worth getting are the Stainless Marine ones - much stronger and not a lot more money!

Justwin · 15 August 2006, 11:19

Quote:

I wouldn't recomend those lifters at all - what makes you suggest those codders? They are only for use on flat lakes in the US - the only ones worth getting are the Stainless Marine ones - much stronger and not a lot more money!

Cookee,

Have you any idea where you can get the S/S ones and a rough price?

Cookee · 15 August 2006, 12:54

I think Tony Davis over on Boatmad.com deals with them on a regular basis - go for a gorilla 3 - they come in 5 or 7 inch height - get the smaller one if you don't need the extra height.