Patching holes on a boat

I bought a 14ft family speed boat that has had a few bits stripped off it.
Cleats,small fitments on the hood etc.The previous owner as filled the fixing holes with
silicon,and painted over them.
Some of the holes go through the "Gripper anti slip tape"
I intend to cover the holes with fine f/glass tissue once the silicon has been removed and the areas sanded down.How would I go about removing the anti slip tape?
There are no holes in the hull,it has never been damaged or drilled into.
The auxiiary engine bracket had been removed,and I have replaced it with a new one,I covered the old holes with a 20mm grp board and made new fixings through that.
There are two fixing holes that have been filled with silicon below the deck level on the transom,which are below the drain bung for the deck.These bother me a bit because the hull to deck is a sealed compartment,with no means of draining,and if it ships water I would have no way of knowing.Would fine mesh f/glass tissue do the job?
I intend to do as neat a job as possible of course,but the boat is for sea fishing and doesn't
need to look pristine.
Is it possible to feather sand through the gelcoat and overlap it with the fibreglass,or does it need to be f/glass to f/glass?
Just the last few fiddly bits before I get it on the water.
Any advice will be greatly appreciated.

 

You can remove the tape by first heating it. If you have a heat gun or a hair dryer is enough. The residue can be then cleaned with a solvent. They make a slow drying product for it that works great.

 

Dig out the silicone. Acetone and petrol are reasonable at cleaning quite a few adhesive residues from stickers and tapes. I hate silicone for 'hole' plugging on old holes like you have, it's just cheap and only holds for a while, drill it out if necessary. Just have to make sure the bond surface really is clean for the epoxy filler to work.

You should fill any holes with epoxy and a filler, microfibres, glass etc. Then gelcoat over. If you need to reinforce the structure, yes you need to remove the gelcoat, build up the glass - can be all polyester, then regelcoat.

If you have any holes through the hull ie screws into unbacked parts, you need a drain and a hatch. Also the expansion contraction even on a single day is not good for a 'sealed' hull - worse if not all white. Easing a hatch cover slightly to allow slow breathing is a wise idea, as well as allowing you to get the moisture out with a sponge etc. Alternatively put a 1mm hole through the hatch cover, it won't leak but air can go either way.

 

Hi Gonzo,thanks,
I have a heat gun,I also have 5ltrs of Acetone for removing the residue(I won't be using
all of it of course)

 

Hello again SS,
Fortunately none of the holes need reinforcing,the only ones that will be below the waterline are in the bottom two corners of the transom,they are about 15mm dia.I can't imagine what their purpose was.I can build up the tissue neatly over them and sand them over and regelcoat like you suggest.
For piece of mind I'll fit a small hatch cover like you suggest.
The little patches of silicone are taking the edge off the look of the boat,which is a shame
because the boat is quite presentable.
Thanks for your advice.
"V"

 

The two holes were probably drilled there to drain the cavity below your deck, you might consider installing garboard drains at those locations so as to facilitate removing any water that accumulates in there.
Gerald

 

Thanks for that info,I can see now what they were for.Drains are a good idea.
I put a straight edge online with the drain bung across the transom,the holes are inline with the bung just above the deck level.So at some point there must have been 3.
They will still need glassing over for peace of mind though.
The hull has a shallow draft,so the cavity between the deck and hull has not got a lot of volume.
Thanks for your input,much appreciated
"V"