Fitting davitts to a Princess 33

[kcollins]

Hi Folks,

Does anyone have experience of fitting davitts to a Princess 33? I am wondering what type of reinforcement might be necessary. I only want to carry a small dinghy and a 4hp motor. Would appreciate any help.

 

[markdj]

If the lay up is thick which it probably is, then finding a spot and use a plywood backing which will spread the load on the fiberglass.

 

[oldsaltoz]

G'day Hebe,

We have repaired many boats poorly fitted davits, decks lifting or transoms deformed.

Most of them were just too small to carry davits and were never designed to.

If you must have them get some professional advice and an inspection done first.
a small dinghy and a 4hp motor may not sound like much but add the weight of the davits and any strengthening required than add this to some water drums outside the stern rails and see how far she goes down at the stern.

Take care.

Andavagoodweekend......

 

[PCUK]

When I fitted huge Simpson davits to a Senior 31 I made up a 3/8 inch thick steel bracket that bolted down the inside of the transom and under the aft deck so the davits could be bolted through to spread the load. With a heavy dinghy I never had any stress problems. Coated the bracket with Waxoyl and it never rusted either!

 

[asteven221]

I used to have a P33 with davits. I don't think I have seen a P33 that has not got davits fitted, so I am surprised your's hasn't got any. I am assuming you are talking about one of late 70's vintage but if not - ignore my comments. Assuming it's 70's then you should be able to fit them fairly easily as the inside of the deck area is accessible and the deck is flat where you would mount them. Buy the davits and glass in a good backing pad for strenght and you should be fine.

 

[markdj]

One thing that has recently come to light is point loading when using steel for a backing plate. The steel is stiffer and if the surface is not enirely flat which I'm sure all installs wouldn't be then the very edges of the steel are digging in and subjecting the fiberglass to additional point loading which is way I have come to think that marine plywood which is a bit more flexible would spread the load better. Of course there is the problem then of rotting but if the bolts are sealed and then large washers used on the ply it should be the best option.

 

[oldsaltoz]

When fitting backing plates the area between the plate and the hull / deck or other,
Must be filled with a solid leveling compound.

Mixing resin and Micro-fibres makes an excellent filler in this application, providing an even load spread over the total plate area, any point loading cracks are an indication the backing is too small allowing the deck ' hull or other to flex too far.

Method: Mix resin and hardener or catalyst as required, add micro-fibres and mix till you have a paste about the same thickness as peanut paste.

Spread this on the backing plate and offer up, fitting thru' bolts and nut. Do up the nuts with your fingers only leaving a gap between plate and surface of 3 to 8 mm.
Clean up any resin that is pushed out when still wet, because this stuff is hard to sand back later.

If you think you will have to remove the backing plate at some time later, place some cling wrap on the hull / deck before you apply the plate.

I hope this helps,

Avagoodweekend......