Hole in the hull (creation of)

[No1_Moose]

Toscana will shortly be receiving a new fish frying transducer thingy. Moose_Snr is all for paying someone to come along to drill the hole and fit the fish frying device. I on the other hand am all for doing the drilling e.t.c myself.

Anyway, is there a technique to GRP hole in the hull creation? The way I see it is:
a) Buy decent hole cutter
b) Place newly acquired decent hole cutter in drill
c) Introduce hole cutter to GRP in chosen location
d) Depress the noise button
e) Splash sikaflex waterproof sealant around hole
f) Stick fish frying device in hole and tighten nuts
g) Allow to dry
h) Re-introduce boat to sea
i) Receive warm glowing feeling when the bilge pumps don't start running


It isn't difficult is it??? Or should I back down and allow Moose_Snr to call unproven and probably quite dodgy "boat person" in to do the above?

 

[Sixpence]

As always the choice is with the owner , and yes you do get a warm feeling when it all works out , but if it doesn't work out and the cold wet feeling starts and you only have yourself to blame ? . If you're not 100% sure , get someone in to do it but make sure they're insured and arrange to chuck her back in before your man runs off with the loot

 

[peterb26]

Cant you get a "Through-Hull" transducer and save all the worrying stuff?

If you can then all you need to do is to mount an oil-filled tube on the inside of the hull and lower in the fish-fryer!

 

[fireball]

Cut it yourself - it isn't rocket science!!

Make sure you get a hole saw of the right size - it'll say what size it should be in the manual.
Cover the area to be cut with masking tape - it helps stop the spintering as you start the cut.
Once you've started cutting, withdraw the saw and check to see how thick the hull is. It's a good idea to do 1/2 from one side and 1/2 from the other.
Once you've got the hole ensure the fitting actually fits - you may need a file just to finish it off.

Get yourself plenty of sikaflex.

Easy see!

Oh - forgot to say, take your time, don't rush it. /forums/images/graemlins/ooo.gif

 

[Wiggo]

Agreed. The important bit is probably to watch out for the thickness of the hull - you may be surprised and a normal holesaw may not be deep enough to go through from one side alone. I put a filler in the side deck for a freshwater flush tank, and the side decks are over 3cm thick, so got knows what the hull will be.

 

[rickp]

To save him the trouble:

<oldgit>Aren't all sealines made of paper-thin GRP?</oldgit>

Rick

 

[Whitelighter]

[ QUOTE ]
To save him the trouble:

<oldgit>Aren't all sealines made of paper-thin GRP?</oldgit>

Rick

[/ QUOTE ]

/forums/images/graemlins/grin.gif

 

[bigwow]

Drill a small pilot hole first, just in case there is an obstruction inside and it's in the wrong place. A small hole is easier to fill than one done with a hole cutter.
/forums/images/graemlins/laugh.gif

 

[fireball]

We put a hole in the bottom of a MacWester Rowan a few years ago (on purpose!) It was about an Inch thick. Newer boats are generally much thinner!

 

[duncan]

[ QUOTE ]
Drill a small pilot hole first, just in case there is an obstruction inside and it's in the wrong place. A small hole is easier to fill than one done with a hole cutter.
/forums/images/graemlins/laugh.gif

[/ QUOTE ]

just run the hole cutter location drill on it's own first............then start the cutter from the outside to get a clean cut on the gell, move to inside to complete the cut.

Moose - know how you feel - cutting the hole in the hull for the eber exhaust was a huge mental strain; measured it so many times I confused myself! Even the relatively small one in the transom for the transducer cable (went that route) was difficult to 'start'.

Personally I would rather do it myself slowly and with a degree of attention that a professional couldn't afford (to charge you).

 

[omega2]

Why drill hole, take transducer place in plastic bag add a little water, wet the outside of bag, try positions in bilge were a good return is found by watching monitor, when found mark with a pencil. Take transducer from bag, hang over board in clear water, note return echo, if same as first echo, then build a tube in hull to accept transducer and fill with oil, or do as we have done just sand the in hull area flattish and stick with slow curing epoxy.

 

[omega2]

Forgot to mention the hull has to be solid glass, not a sandwich.

 

[Poignard]

You missed out:-

"Seal exposed edges of fibreglass with epoxy resin"

 

[omega2]

Fish fryers

This is the return on ours, with the transducer sitting in a puddle of water in the bilge, although the instructions were to drill holes and mount outside, try it you may be amazed

Oh, and the echoes were small Bass.

 

[tcm]

Hm i think iwould definitely like to have a jig for the drill if poss, to keep it at 90 degrees and avoid the thing ouch oops jamming in the ever-deepening hole, and it would have to be a flippin decent drill too. At the very least you need a pilot hole, esp if your dad is a pilot.

 

[tico]

Would suggest that the first action (before 'a') would be...





.. Remove boat from water !!

 

[Lakesailor]

In addition be aware that as the cutter bites the flat surface it can grab violently. If you used the pilot drill first then added the cutter it's better.

I've just cut eight 2" holes through 2" thick Iroko easily. Blocks of wood, not a hull.

 

[Talbot]

Although use of a pilot hole first has been mentioned. There is a big ommission.

Drill your pilot hole from inside the boat. That way you ensure that the hole is in the right place.

Doing some of the hole from one side, and then finishing from the other is a good way to minimise breakout, however, dont forget that when doing this inside the hull, there will be quite lot of fiberglass dust in a confied environment - wear a dust mask, and preferably some eye protection as well.