Someone's screwed through through my hull...

Yellow Ballad

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Well it was probably their hull when they did it but after washing my hull off after my winter haul out I noticed a screw through the GRP just infront of the log wheel.

A can't see the screw from the inside as there's a glassed in battery tray above the area but I can feel the screw thread underneath penetrating through the grp (infact I can feel two there's another a few inches behind (you can just make it out in the picture)). It's not screwed into a backing pad just straight through the glass (under the water line)! I have no idea what it's for, someones suggested a "weed" deflector for the log, I though possibly a hull anode as the batteries are above it? Either way it's not doing anything and I'm a little uncomfortable having a couple of screws through the GRP (even though they must have been there for the last 30 years as the previous owner is just as surprised to see them as I was). They must have had gelcoat over the top of the head as the previous owned has taken the bottom back to gel twice in his ownership and has never seen them.

What's your thoughts?

I can either plug them with thickened exoxy and flocoat over the top. I assume that's what it was like before and I dislodged the plug cleaning the hull.

Do the above but cut the battery tray out (I'm planning on relocating the batteries anyway) and glass over the top of the threads as a backup.

But I still have two random screws sticking through my hull.

Or remove them and bevel inside and out then glass the holes The head is only about 10mm across so will I need to make the bevel larger then normal?

Or listen to the PBO collective.

All suggestions and advice listened to..

Tom

20171104_055940.jpg
 
Got to say, that I can't really see a problem here, but there again, I've a wooden boat with hundreds of screws through the hull! Would a 'splodge' of Araldite over it assuage any angst?
On the positive side of things, whichever option that you take, will almost certainly be a good one, as there's not a great deal that's going to be bad from this! :)
 
If you can reach the inside OK, would probably just clean up the thread and little of the surrounding area with a clean cloth and a bit of solvent and then push a ball (a couple of cms across) of epoxy over them a spread in over the threads and the GRP. A water setting epoxy like Milliput would be perfect.

Richard
 
Maybe not a problem on a wooden boat, but anything that can let moisture into the substrate could be an issue on grp, probably won't be an issue but could be.

I'd remove them, drill out the hole slightly oversized and check for any moisture ingress, maybe heat gun it out just to be sure. Countersink both sides generously, tape the outside and poor liquid epoxy in, and then a couple of small circles of cloth over the top in the interior just for peace of mind, job done.
 
Been there 30years... no sign of a leak.. epoxy over and forget?
But...
If the screws come out (or drill them out)...

No need to do fancy bevel.

If you can get to the back a small strip of matting and fill the hole would probably be fine.

If you can't get to the back. Stick a counter sinking drill bit in there to clean it out a touch. Take a piece of sponge. Dunk in some catalysed resin or some unthickened epoxy and give it a good squidge. Roll it up thin and push into the hole. (Behind the hole it will expand preventing it from being able to fall out of the boat int Leave to cure. Cut flush to surface then re-countersink it. Apply Gel/Flow/Epoxy filler of choice creating a cap on the plug preventing it from pushing into the boat under water pressure.
Sand/polish/finish as required
 
Thanks for the replies, I don't really fancy glassing it up this year if I can help it so I think an epoxy plug will get me through next year (the winter boat job list is pretty full as it is). I don't really like the idea of them poking through the grp but they're not going anywhere and haven't for the last 30 years, there's no leaks. The putty idea isn't a bad backup to keep my mind at rest.
 
Surely there must have been a reason for them to be put there in the first place and if you are not 100% sure what the reason is then you are better off leaving them in situ. They look to be countersunk and that implies that whatever they are holding is on the other side of the hull.

If you can get to the other side then you can remove them and fill the holes - but I would have thought just plugging and fairing would be fine.
 
Surely there must have been a reason for them to be put there in the first place and if you are not 100% sure what the reason is then you are better off leaving them in situ. They look to be countersunk and that implies that whatever they are holding is on the other side of the hull.

If you can get to the other side then you can remove them and fill the holes - but I would have thought just plugging and fairing would be fine.

Yes they are countersunk, maybe a mm below the rest of the gel. I've done my best impression of a teenage lad trying to touch his girlfriends lady bits for the first time and got my hand under the battery tray, you can feel the inside of the hull nice and smooth then the screw threads sticking through maybe 10-15mm with nothing else around that would be fixed into it. I'll take my inspection mirror down next time.
 
Rather than faff around with epoxy, you could just balance a blob of CT1 sealant - or Sikaflex if you fancy 'posh' - on your fingertips, then smear that over the protruding point(s). That'll do nicely, for as long as you choose to take to remove the screws and fill the holes. Maybe years....
 
I have noticed small fins on some hulls, behind or in front of the log (I can't remember the position) but I am sure if you look around hulls on the hard standing you will see one. The screws are probably from mounting one of these. As others have said, don't worry about them.
 
I had something similar on my Corvette - just errand 4mm machine screws through the hull for no apparent reason. Mine were about 1.5" from the engine inlet seacocks. When I replaced the seacocks with Forespar Marelon the backing pad entirely covered the hole into which I gave a good squirt of Sika 291, with a good bead right around. Then I just smoothed of the excess outside and until now had completely forgotten about them.

In your case the head doesn't look at all pink, so if me, I would just re-fair with some araldite, or epoxy filler, and find something else to worry about.
 
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