Securing my outboard.

[Spindrift]

Hi All,

Right then, at last I have united my boat with it's engine. The two have never been formally introduced until now, having just been on nodding terms in my garage. However, yesterday afternoon I hung the engine, a 1962 Kiekhaefer Merc 500, on the transom and together they look handsome. (Move over, Carol Duffy!)

My question is about securing it further. What sort of fixing I should now use to bolt the engine through the transom itself? I think I can get some sort of locking bolt which makes it all but impossible for someone to steal the engine (never say never, of course), and obviously it needs to be fixed by more than just the clamp screws. The problem is, I have no idea what size, or how I should seal around the fixings once they are in place. I'm guessing broad stainless washers with a smear of some sort of sealant (Sikaflex?) around them would be best.

Unfortunately, I didn't measure the width of the slots in the outboard's clamp bracket. What have other owner's of similar engines used?

Any info will be gratefully received, as ever. Otherwise it is a 70-mile round trip to the boatyard just to check this measurement!

Thanks

[sean-nós]

As far as I remember the bolts are 1/2 inch or 12.7 mm and the holes 17/32 in 13.5mm then just coat them in sealant, my boat had a wooden transom so I drilled my holes oversized and filled them with epoxy then when it was set I drilled out to 13.5 leaving a ring of epoxy to protect the wood and sealant around the bolt to make it watertight .

[Alacrity]

What Fergal says above ^^. I use stainless steel coachbolts they locate in the slots in the clamp & then use big (more than one if they are thin) stainless penny washers on the inside with self locking nuts. Plenty of sealant on the bolt before fitting & again under the washers. Fergal's method is the best (with the epoxy sealing the wood) as it should protect the wood completely. Involves fitting & refitting the motor twice I would think but worth it in the long run.

[Spindrift]

Thank you, both, for your answers; much appreciated. That's next Sunday sorted, then! Laying hold of 1/2" stainless bolts (or metric equivalent) will be tricky in the time I have but at least I now have a plan.

There used to be an excellent engineers suppliers' in Chadwell Heath who would sell you as many or as few components as you needed, but sadly they closed down last year. Up until then they had supplied all the fixings for my boat. My nearest supplier now only sells wholesale, with a minimum quantity of 1 box. I imagine that 1 box of 1/2 " stainless steel bolts would have a limited market, even amongst our community! I'll try some chandlers and will let you know how I get on.

What sealant would you recommend, by the way?

[Alacrity]

Try A2A4 Fixings here

I am not sure on a type of sealant. Sikaflex is good but make sure it is designed to be used underwater. Any decent chandler or boatyard will be able to help/advise.

[Spindrift]

Bag of nuts, anyone?

I've just looked on the Screwfix site. I can get a pack of 10 x12mm stainless bolts (OK, so I'll have a few left over) for a little under £7.73. Equally, I can buy a pack of ten 12mm penny washers. £2.82.

But then I have to buy the nuts. Nuts only come supplied in packs of ..... 100. And how much for 100 A2 stainless nylock nuts? That'll be £20 to you, sir!

Good grief.

[Scuben]

Fleabay is often good for small quantities of stainless fixings if you can't find anywhere locally.