help in fitting snap davits to my S37 transom

[lanerboy]

hi all

i want to fit some snap davits to the transom on my s37 just above the rubbing strip, the problem i have is i wish to fit them off set so i can still get on / off the boat without the tender getting in the way.

i have been in the engine bay and there is a box section made from 1 inch ply that is part of the boats construction and i cannot get inside this box so i am unable to get any nuts on the bolts from the inside.

has anyone fitted any davits to the transom using self tapping style screws, i am worried about doing it this way as when inside the engine bay i can see the fibreglass is almost transparrent so therefor i doubt it will be strong enough to hold the weight of the tender and may give way and break off.

below is a pic of where i would like to fix the davits on the transom, the starboard side one is not a problem as i think i can get to the inside of this one to get some nuts on it but the port side one will end up inside the box section

below are some pics rafiki kindly took and sent me of a S37 with the same davits as mine but they have spaced theirs differently

 

[MrB]

Can you drill a hole big enough in the box to get a socket and extension bar through for the nut on the inside? Or can you find bolts long enough to go right through the box? Just an idea.

 

[lanerboy]

Can you drill a hole big enough in the box to get a socket and extension bar through for the nut on the inside? Or can you find bolts long enough to go right through the box? Just an idea.

i did think about drilling a large hole big enough to get my hand through as you suggest but still unsure

below are a few pics of the box construction please note they are hard to work out without actually seeing it in the flesh one pic from each side

 

[MrB]

You wouldn't need a hole big enough for your hand just one big enough for the socket and extension bar. A dab of grease or bluetack to hold the nut in the socket while you offer it up to the bolt.. It would be easy to glass the hole back over if you felt it needed it too.

 

[lanerboy]

i need to be able to get a decent sized plate on the inside to help spread the weight

 

[nimbusgb]

How about fitting a couple of dinghy hatches, the round screw in ones. can then keep the box sealed and can get in and to the nuts at will and it looks professional

 

[MrB]

Ok how about cutting the hole with this. http://http://www.screwfix.com/p/armeg-solid-board-cutter-111mm/93432#product_additional_details_container You can get your hand and plate in then use one of the rebated cover plates to fill the hole back in. Nice an neat.

 

[lanerboy]

not sure if there is anything inside the box as the electric supply comes in directly above it

 

[lanerboy]

someone off the sealine forum suggested using toggle bolts for the port side one which i thought was a good idea

 

[MrB]

They wouldn't be strong enough as they are generally used for plasterboard. But, on that note i just found these. http://www.toomerandhayter.co.uk/products/detail/?id=877&cat=71

 

[lanerboy]

They wouldn't be strong enough as they are generally used for plasterboard. But, on that note i just found these. http://www.toomerandhayter.co.uk/products/detail/?id=877&cat=71

sorry i meant to say use a type of toggle bolt like in the above pic but made from marine grade stailess like the one in your thread good find that

 

[lanerboy]

Mr B

i think you may have solved my problem

here is a video of one being fitted into a wall but you get the idea

 

[rafiki_]

Shawn, I'm not convinced that there will be sufficient load baring support on the inside of your transom wall to prevent cracking and crazing.

 

[Thepipdoc]

Shawn, I'm not convinced that there will be sufficient load baring support on the inside of your transom wall to prevent cracking and crazing.

Neither am I.
I wouldn't hang a dinghy of a couple of these fixings.

 

[Elessar]

hi all

i want to fit some snap davits to the transom on my s37 just above the rubbing strip, the problem i have is i wish to fit them off set so i can still get on / off the boat without the tender getting in the way.

i have been in the engine bay and there is a box section made from 1 inch ply that is part of the boats construction and i cannot get inside this box so i am unable to get any nuts on the bolts from the inside.

has anyone fitted any davits to the transom using self tapping style screws, i am worried about doing it this way as when inside the engine bay i can see the fibreglass is almost transparrent so therefor i doubt it will be strong enough to hold the weight of the tender and may give way and break off.

below is a pic of where i would like to fix the davits on the transom, the starboard side one is not a problem as i think i can get to the inside of this one to get some nuts on it but the port side one will end up inside the box section

The box is part of an optional liferaft deck locker, to which no lid has been fitted. I've never seen one with a lid fitted..........

Cut a 4" circular hole in it. It wont weaken it, and you can glass a proper backing pad onto the transom to bolt the davits onto.

 

[paultallett]

The box is part of an optional liferaft deck locker, to which no lid has been fitted. I've never seen one with a lid fitted..........

Cut a 4" circular hole in it. It wont weaken it, and you can glass a proper backing pad onto the transom to bolt the davits onto.

Totally agree that you need a proper backing pad to spread the load as you just don't know what layup the fibreglass has in the spot you want the fixing. Sounds like Elessar has your answer but I would give sealine a quick call and see what they say.

Good luck.

 

[Blackfeather]

At the risk of repetition, I would be very careful about using anything other than serious bolts, tightened and lock thread used, even if they are very long. The strains on those fittings when underway are substantial - don't underestimate the lever effect when you are bouncing around in a bit of a sea.

 

[lanerboy]

The box is part of an optional liferaft deck locker, to which no lid has been fitted. I've never seen one with a lid fitted..........

Cut a 4" circular hole in it. It wont weaken it, and you can glass a proper backing pad onto the transom to bolt the davits onto.

ok now i know what the box is i will cut a hole large enough to get my arm in and fit a decent size backing plate to spread the weight

thanks Elassar for pointing out what the box construction is for, now i know its empty inside there i can cut the hole with confidence