Drilling through deck

[gasdave]

I wish to install one of these http://www.saltyjohn.co.uk/cableport_boat_product.htm at my mast base to take all 5 cables, including the coaxial connector for when unstepping.

Any tips on how best to cut a 40mm diam hole through the reinforced section of deck just in front of the mast? I think it's about 50 - 55mm thick and I would prefer to angle the hole slightly aft to aid the internal cable exit inside the cabin and avoid a 90 degree turn.

The boat is a Sadler 26 and I'm not sure what the deck construction is here (although an already existing but too small hole immediately in front of the mast step looks as though it goes through solid laminate - I intend to fill this hole to leave only a single cable entry site).

All tips greatly appreciated as always

 

[rob2]

GRP is pretty easy to drill and cut, I've had great success with the cheap hole cutters for skin fittings. The bottom of my boat turned out to be about the same thickness. For best/neatest resultsdrill from one side first and then change to the other side before breakthrough, this will avoid chipping around the edges. Only a small angle will be possible, or you will not be able to cut from both sides, however it would be fairly simple to use a grinder to put a large radius on the underside leading aft for the cables. I presume there is a headlining which will conceal your handiwork!

Rob.

 

[oldsaltoz]

You could fix a block of softwood to the deck with the required angle cut on top and use a hole saw.

 

[gasdave]

I presume there is a headlining which will conceal your handiwork!

Rob.

No headlining as such in the Sadler - it's a hard GRP cabin lining so any "rougher" finish requires additional work to make good!

The angled wooden block is a nice idea - simple!

 

[VicS]

Your Sadler 26 has an interior moulding (Edit ; you have said that while typing)

You will have to drill through the deck, and the interior moulding and whatever (closed cell foam ??) is between them

A hole cutter used from outside on the outer layer and from the inside on the inner moulding is the way to go.

Not sure about the angle though.

Drill a pilot hole right though at the required angle then cut the inner and outer layers straight but offset. Then cut away the foam or what ever carefully by hand. ???

Sorry don't like the wooden block idea. Going to have trouble when the hole saw meets the interface between the wood and the GRP

 

[gasdave]

You will have to drill through the deck, and the interior moulding and whatever (closed cell foam ??) is between them

I did wonder about the possibility of a sandwich construction and I believe Sadler use a foam filling. However the area I am looking at does appear to be much heavier than the surrounding deck/coachroof - which makes sense to me as it is where the mast is deck-stepped. Hence my "hope" that it is solid construction Anyone know for sure?

Otherwise I will also have to deal with the need to seal inside the sandwich. One thought I had for this (and no idea if this would even be feasible !) would be to cut a hole matched for size to take some plastic conduit big enough for the cables. This then only requires to be sealed at the ends and would be much easier than trying to apply sealant into a hole which I want to remain patent.

 

[oldsaltoz]

Two points to ponder.

1) I would avoid weakening the structure bu cutting through a reinforced area, particularly one that supports the mast.

You could make your cut in this area provided you then reinforced the area around the hole.

2) Putting 'a bit sealant' around a conduit is not the way to go, unless you like a soft soggy deck.

The foam should be removed at least 20 mm back from the new edge and replaced with a mixture of resin and Micro-Fibres or finely cut fibreglass. This will not only help support the deck and liner, but also prevent water entry into the sandwich construction.

Hope this helps.

 

[VicS]

You would want to avoid cutting into any strengthening beam that might be there.

Might find some domestic waste pipe a suitable size for lining the hole.

What about posting the question on the Sadler and Starlight Owners Association forum. It appears to be available to non memebers

 

[aquaplane]

Have you tried getting your wires in your fist and seeing how big a hole you need? I would suspect that it's not a right big hole, probably bigger than 10mm but less than 3/4". More of a drill job than a hole cutter.

Sealing the edges of the hole is a good idea but minimising weakenig of the mast step by keeping the hole small is probably good too.

I fitted a coaxial through deack conector to a boat with a 10 or 12 mm wood drill to make the hole, the drill was scrap after as it was blunt but only cost <£10.

 

[SmileyGiley]

Definately remove foam (or whaterver) in the fill and seal. Water ingress to sandwich deck v. likely otherwise. Grrrrr & hmmph.

 

[samwise]

The Sadler foam fill is a great idea until you have to run extra wiring or pipework. Certainly if you are drilling the deck you have to seal it properly because , as has been said, water ingress will cause major problems. If it any consolation, the Sadler 29 was worse!

Haven't seen Old Saltz's fitting but from what you say, the crucial connections are inside the boat, which is good. I have become increasingly disaffected with deck plugs which inevitably lead to leakage and corrosion of the pins in the plug. I now use deck glands with cables leading down under the cabin headlining with proper connectors ( not choc block) so that if the mast needs to come down I can withdraw them through the gland mounting.