drilling into my boat

[cem]

i need to drill some holes..... only screw/bolts in the gunwale (sp) to mount some rail blaza star ports for fishing rod holders (unless someone can come up with a suggestion of one which needs no holes drilled anywhere)...rail mount ones won't work as we have no rails other then a couple of small grab rails and there is no clearance behind them.

now i have drilled my fair share of holes in wood and metal but rarely i GRP what should i be looking for in terms of pilot hole?? very small? the size of the "shank" of the screw ex threads or bigger???

just makes me nervous drilling into the boat SWMBO would rather i didn't drill into anything but rods need to be mounted


thanks in advance

Colin

[Brit Rider]

I guess I'm as qualified as most to help on this as I do it most days.

Size of hole will dictate your drilling method.

If it's over 10mm you'll want to go with a 2mm or so pilot hole (drilled any which way), and then move to the required size hole saw. Start the hole saw in reverse until through the gel... Once you've got through that you can flick to forward and finish the cut.

When drilling GRP always let the drill bit do the work... barely any pressure is required.

If the hole is small than 10mm then just go with 2-3 steps of drill size to get you to the final hole dia. Always drill gel in reverse, low pressure, fast drill speed.

[jokaboat]

What Brit Rider says, the other thing that I would suggest is to make the pilot hole the size of the screw shank which will minimise risk of crazing the gel coat. Also if the hole goes right through the hole a dab of sealant in the hole before putting the screw in would not go amiss.

Basically if the screw is difficult to get in the hole is too small.

Didn't know about drilling the gel in reverse, nice tip

I know what you mean though, I hate drilling holes in boats.

[cem]

thanks for that

it is small 4-5mm holes to take self tappers to hold these mounts in place

[cem]

these are the beasties...http://www.railblaza.com/uploads/images ... Marine.pdf neat system IMO as we are limited for places to mount rod holders ad i didn't fancy drilling a couple of 50mm holes all the way through...(there are control cables in the way on one side of the boat too)

[Capn Jack]

They are the muts nuts, never seen them before and a perfect solution for rod holders.

If the Rib versions are flat bottomed, you could always resin those to the Gelcoat with Epoxy, rather than drill. However, I would go for the drilling it's not that hard and if you follow Brit Riders instructions (nice one Brit Rider) you can't go wrong. I would get some Sikaflex 351 and dob a little around the base to seal of water ingress as well as in the scew holes, it's always worked for me.

Also I found this website the other day, maybe some of you already use them, for me it was like a boy looking into a sweetshop window.......

SEA SCREW

[cem]

yeah they are great, but not cheap, just shy of £30 for a rod holder and mount, a pair of mouts is £20ish and i hate to think how much the bait table thing is , the quality however is pretty special, no rough edges like on most of the rod holders i have seen, well thought out and pretty indstructible feel to the plastic

[dpb101]

These are a good cheaper alternative:
http://www.weymouthangling.com/tackle-s ... od-holder/
can be found for less than a tenner on E Bay
Google Fladen Rod Holder.

[Brit Rider]

You'll want to do plenty of counter sinking for your application too then

[cem]

holes drilled, star port mounts fitted, all in all a very productive day yesterday, did all of the jobs i had planned other than the speedo, needed a foot pump or similar to blow the muck out of it (if that is the problem), but i didn't have anything to hand

[JORIDAPILOT]

I guess I'm as qualified as most to help on this as I do it most days.

Size of hole will dictate your drilling method.

If it's over 10mm you'll want to go with a 2mm or so pilot hole (drilled any which way), and then move to the required size hole saw. Start the hole saw in reverse until through the gel... Once you've got through that you can flick to forward and finish the cut.

When drilling GRP always let the drill bit do the work... barely any pressure is required.

If the hole is small than 10mm then just go with 2-3 steps of drill size to get you to the final hole dia. Always drill gel in reverse, low pressure, fast drill speed.

That is very interesting and useful.
I have to cut a 32mm hole in the top of my coaming. I have the correct hole saw but I would never have thought to start it in reverse.
Great tip.. thanks..

[Centaur]

You could also try putting masking tape over the area first too - it helps to stop the drill bit skidding on the shiny gel coat at the start and also seems to help avoid splintering the gel.

[JORIDAPILOT]

You could also try putting masking tape over the area first too - it helps to stop the drill bit skidding on the shiny gel coat at the start and also seems to help avoid splintering the gel.

Another good tip worth remembering although I know about this one and have used it on many occasions.

It is too easy to get too small a pilot hole in GRP, you need a much bigger hole than you would in say timber, I have actually sheared off a stainless screw (cheap one) because the pilot hole was too small. Get it right and it feels right, so said the actress

[Brit Rider]

Masking tape is well worth it.... not just for the drill bit tip but also for marking before you start drilling.

Always remember the golden rule:
Mesasure once.
Measure again.
Measure more.
drill!!

[jokaboat]

Masking tape is well worth it.... not just for the drill bit tip but also for marking before you start drilling.

Always remember the golden rule:
Mesasure once.
Measure again.
Measure more.
drill!!

You missed a bit,

Get the filler out then repeat