Through Hull Fittings, Replacing and Glassing Over Holes

[knuterikt]

Another west system guide http://www.westsystem.com/ss/repairing-machined-holes-in-fiberglass/

We replaced all with new from true design four years ago, still working as new.

 

[Melleman]

I replaced mine with TruDesign fittings- very easy DIY job and they're a pleasure to use. No more arm wrestle to operate the bigger sizes.

John

+1

 

[rogerball0]

Just fitted two of my Shakewells last night, look pretty Gucci from every angle, l like the look from out side the best:

Other pics here: https://picasaweb.google.com/lh/photo/a0tBskbKds7ztDwRmxNqxdMTjNZETYmyPJy0liipFm0?feat=directlink

Roger

 

[thalassa]

I replaced mine with TruDesign fittings- very easy DIY job and they're a pleasure to use. No more arm wrestle to operate the bigger sizes.

John

+2.

 

[Spirit of Glenans]

I went with these from www.shakewell.info no skin fitting necessary, bonds directly to the hull

The possibility of taking out the works and replacing with a blanking cap makes these very interesting. I was a little perturbed at your statement that they "..just bond directly to hull", but was reassured to see in the diagram that they bolt through. A retaining ring on the outside a la Blakes would give me even more confidence, however. I wonder would they be brittle in cold temperatures?
Can anyone else give any feedback on these?

 

[rogerball0]

The possibility of taking out the works and replacing with a blanking cap makes these very interesting. I was a little perturbed at your statement that they "..just bond directly to hull", but was reassured to see in the diagram that they bolt through. A retaining ring on the outside a la Blakes would give me even more confidence, however. I wonder would they be brittle in cold temperatures?
Can anyone else give any feedback on these?

Theres been problems i've read about on a couple of U.S sites regarding Marelon breaking and seizing but i think thats mainly due to lack of maintainance and the fact Marelon are the only ones that sell in volume so you probably hear a bit more about them although i liked the bit on Shakewell' site about Martela OF staying afloat for quite some time due to the air tight seal created by these seacocks.

Personally speaking i dont have a problem bonding anything with epoxy, i've conducted many a hammer test using epoxy and various substrates and see no reason not to go this route plus the amount of time and effort saved fitting these made it a no-brainer for me.

From drilling two holes through the hull to washing up the rollers in acetone afterwards took 1.5 hours to fit both, also i like the simplicity of these, the Marelons have screws and moving parts where as the Shakewells are basically a locking plunger secured on a thread, doesn't get much simpler than that.

 

[nigelmercier]

I ... was reassured to see in the diagram that they bolt through...

Looks like they can be bolted, or glassed in.

However, I would never buy such an important item from a company with a gmail address.

 

[mattnj]

Ok, so I ground out all the fittings this weekend, they were all in one hell of a state, especially the valves, the through fittings were ok (bronze) but some were lose at the backing ply had rotten away.

Each of the fittings had a 100mm square bit of 8mm thick ply between the hull and nut on the inside which were all rotten and manky and had actually cause a few of the fittings nuts to be lose! The previous owner seem to have then glued over the top, I take it I don't need to be putting these ply pieces back in? They seemed to be causing more problems than doing good, from memory all my previous ones were nuts straight on to the GRP.

I have just priced up the bits, skin fitting, ball valve, tails, 3 x 1.5", 5 x 3/4" :-

All bronze from ASAP £573
All DZR from ASAP £434
All TrudesignPlastic £423

There doesn't seem to be much in the prices, access is decent to all of them, so based on prices, think I will got for Plastic. Took me 3 hours to grind out the 13 fittings (only putting 9 back in), remove hoses etc, I will report back with final results.

If I do go bronze then am I correct in saying that I DO NOT bond then, seems to be lots of options!

 

[mattnj]

Any idea what a yard would charge to glass over two through hull holes?

They have quoted me "about" 2 hours work at £50 an hour for 2 x 1.5" holes and 2 x 3/4" holes, fittings removed, easy enough access.

 

[nigelmercier]

They have quoted me "about" 2 hours work at £50 an hour for 2 x 1.5" holes and 2 x 3/4" holes, fittings removed, easy enough access.

That sounds awfully quick. I would imagine it takes an hour or so to cut back the GRP.

I'd go with the DZR option.

 

[mattnj]

That sounds awfully quick. I would imagine it takes an hour or so to cut back the GRP.

I'd go with the DZR option.

the question was "Any idea what a yard would charge to glass over two through hull holes" so it was assuming they are ground out....
the guy popped round and explained how he wanted it ground....the 2 hours to glass over.

 

[oldsaltoz]

Filling in the holes in not a time consuming job.

I use a 40 grit Concrete grinding disk, first tape a paper plate inside the hull, this will give you some clearance between the glass you are grinding and the plate,
it's there to prevent dust inside the hull when grinding the outside.
Next, remove the plate and grind the inside to the profile so you end up all but flush with the edge of the outside cut.
Now get out of the boat, do not clean up yet. Just cover the internal hole with some plastic.

Next, with the plastic sheet over the inside of the hole, start laying up the outside, starting with a small patch and progressively
placing larger patches till you are a mm or two below the surrounding profile. 30 to 45 minutes so far.

Then, get back inside and do a good clean up of all the dust generated,
this will allow some time for the outer layer to get tacky and be ready for coating without having to sand it again.
Lay up the inside as before with small patches first and building up, but this time continue placing larger patched till
you have at least a 50 mm overlap onto the inside of the hull.

The next day you can cut the holes and put the fitting in to get an idea of how much material you need to add/remove on both sides
to a get a neat fit.
Make sure you have a small gap on both sides, better to grind a small hollow than leave a lump.
Than install a temporary washer made of plastic (Ice cream container material is good) and add some resin mixed with Micro fibres, then part way tighten the fitting and leave it cure.

Next day remove the fitting, add some sealant and refit the through hull fitting but do it up finger tight, then the next day fully tighten.

No timber to rot out, hull is now stronger than original.

Needless to say this is using an epoxy resin.

Good luck and fair winds.

Total time required to complete in fitting.
Grinding the outside, 10 min's, Inside 15 min's, lay-up 15 min's per side.
Cosmetics, sand and fill around outer fitting using Micro Balloons, 20 min's to apply 10 min's to sand and 5 min's to add extra resin coats.

Good luck and fair winds.