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Filling holes is GRP

mibix

By mibix
in Boat Building & Maintenance

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mibix Explorer

mibix

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We want to go up the Oxford canal from Reading in our little GRP cruiser. Only problem is we're a bit too wide. The corner fenders take us up to 7'4", and max size is 7". Without the corner fenders we are 7' exactly, so it's going to be a squeeze anyway...

 

If we take the corner fenders off there may be holes straight through the hull where they were drilled in and we want to fill them in, as they go slightly underwater when moving, and going up locks...

 

I've been told that epoxy putty is the best thing for the job. Will the plumber's putty be the stuff? This stuff...? http://www.toolstation.com/shop/Painting%20&%20Decorating/Fillers%20&%20Putty/Plumbers%20Epoxy%20Aqua%20Repair/d150/sd3169/p59360

 

Also, anyone know if this stuff is any good? http://www.toolstation.com/shop/Adhesives+Sealants/General+Sealants/Polyurethane+PU40+Sealant+300ml+White/d180/sd2350/p67949 it's Polyurethane based.

 

Cheers

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PhilR Experienced

PhilR

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I haven't bought any recently, but Milliput will be ideal for your requirements. It sets underwater too. You should find it in any decent hardware shop.

 

It is a two part epoxy putty and it isn't messy to use. I reckon it is an essential spare to keep in any toolbox and should only cost 2 or 3 quid.

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Phil Ambrose Veteran II

Phil Ambrose

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I lived on a GRP cruiser for 10 years plus had a few GRP day boats, dorys,dinghys etc so have done a few repairs over the years. I don't know the products either but for what you need to do go with epoxy putty, just cut a bit off need between your fingers till its a uniform grey and press into the holes. Moistening your fingers while kneeding will prevent it from sticking to your skin.

Phil

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Murflynn Veteran

Murflynn

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You haven't said if you plan to replace the fenders later.

There are plenty of products that can be used to make either permanent repairs or temporary repairs.

If the holes are above the static waterline they are only going to suffer from splashing (as long as you are not related to Phylis rolleyes.gif )

For permanent repair I would mix an epoxy filler using a kit bought from the swindlers, comprising epoxy resin, hardener and microfibre additive. The key is to prepare the hole well inside (if possible). This is not the same product as 'epoxy putty'.

For a temporary repair I would use a good adhesive sealant - your swindler will guide you. I used Bond-It PU18 polyurethane for bonding rope fender around the gunwale, it is like a very hard rubber when cured - very cheap on ebay and very easy to use. Cleans up with white spirit.

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John V Veteran

John V

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If it's only a few days you don't want to use something that will be a pain to remove.

There will be screams of outrage at this but.....

when I needed to stop up some holes for a short trip on some bumpy water I used waterproof Gaffer tape inside and out.....After all if you are only talking of some tiny screw holes, Keep an eye on it . If it leaks bung a bit more tape on!

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gazza Veteran

gazza

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If it's only a few days you don't want to use something that will be a pain to remove.

There will be screams of outrage at this but.....

when I needed to stop up some holes for a short trip on some bumpy water I used waterproof Gaffer tape inside and out.....After all if you are only talking of some tiny screw holes, Keep an eye on it . If it leaks bung a bit more tape on!

Correct answer!

 

I'd go with that as well.

 

Two well proven rules.

 

If it moves and shouldn't - gaffa tape.

If it doesn't move and it should - WD 40

 

:-)

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mibix Explorer

mibix

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Posted (edited)

Cheers for all the tips guys. So many different approaches!

 

The holes won't be under the waterline when stationary. But the wake from cruising submerses them. Some more ballast on the bow might help a bit too.

 

We will want to put them back on when we're back on a broad canal/river. No idea how long we'll be on the Oxford canal, but we're thinking of heading north anyway so they might be off a long time.

 

I've no real access to the rear of the holes, as they are deep in the hull, under the diesel tank and storage floors.

 

I don't really want to put screws back in as It might make the holes bigger and cause a problem when re-fitting, and gaffer is not really suitable as it's going to be underwater for the few days going up the Thames.

 

 

I lived on a GRP cruiser for 10 years plus had a few GRP day boats, dorys,dinghys etc so have done a few repairs over the years. I don't know the products either but for what you need to do go with epoxy putty, just cut a bit off need between your fingers till its a uniform grey and press into the holes. Moistening your fingers while kneeding will prevent it from sticking to your skin.
Phil

 

@Phil, will the putty in my OP do the job? I don't really have access to internet delivery at the moment. Just need something I can buy off the shelf in Reading.

 

EDIT: I've just found some Milliput at HobbyCraft in Reading. Is this stuff better than the Plumbers stuff in my OP?.. http://www.hobbycraft.co.uk/milliput-standard-yellow-grey-two-part-epoxy-putty/569176-1000

Edited by mibix
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Naughty Cal Veteran II

Naughty Cal

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If it was only a day, I would. I could be on narrow canals for months. Don't fancy trusting it all on some gaffer!

It's surprisingly resilient stuff!

 

Other option as said above is epoxy filler finished off with gel coat filler. Any chandlers will sell the stuff or Ebay.

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Guest

Guest

Posted
Posted (edited)

If it's only a few days you don't want to use something that will be a pain to remove.

There will be screams of outrage at this but.....

when I needed to stop up some holes for a short trip on some bumpy water I used waterproof Gaffer tape inside and out.....After all if you are only talking of some tiny screw holes, Keep an eye on it . If it leaks bung a bit more tape on

For temporary I would knock some wooden plugs in with a bit of sealant as an adhesive and cut off flush if it is just to stop splashes entering, I agree gaffer tape would do the job if only temporary.

Permanent for me would be a mat/resin patch inside, with a suitable filler from outside. Don't know if it is still about, but have used "Plastic Padding" in years gone by.

Edited by Guest
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Phil Ambrose Veteran II

Phil Ambrose

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I think this thread is now getting out of hand now, the OP said he needs to plug some self tapping screw holes on a temporary basis, maybe a few months and after this period he wants to re-attach his corner fenders.

So Gaffer tape is not the solution, neither is drilling out the holes to take nuts and bolts (he can't access the inside anyway) and using glass mat, gel coat filler are way to permanent.

In short the only sensible solution is as Catweasel suggests, wooden plugs and sealant or as the OP (and others) suggested...epoxy putty.

Phil

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Barry Veteran

Barry

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Posted

I think this thread is now getting out of hand now, the OP said he needs to plug some self tapping screw holes on a temporary basis, maybe a few months and after this period he wants to re-attach his corner fenders.

So Gaffer tape is not the solution, neither is drilling out the holes to take nuts and bolts (he can't access the inside anyway) and using glass mat, gel coat filler are way to permanent.

In short the only sensible solution is as Catweasel suggests, wooden plugs and sealant or as the OP (and others) suggested...epoxy putty.

Phil

 

I agree we should be focusing on the teporary solutions to answer the op's question but I suppose the subject is bound to expand with discussion.

 

Another temporary solution perhaps. Buy some screws of the same diameter and pitch as the ones coming out (assuming they are not machined bolts secured by nuts on the inside) only short enough to compensate for the thickness of the corner fender flanges. Whip the offending corner fenders off and replace them with penny washers held in by the new shorter screws. Plenty of sealant down the screw hole and under the penny washers should keep the water out nicely temporarily if not permanently..

 

I got the idea from fixing a petrol tank on my car a good few years ago. I ran over a stray piece of andle iron in the road and it flipped up and punched a small hole in the petrol tank. When I got home I got a self tapping screw, a penny washer, made a rubber washer from somthing or other and screwed the self tapper into the hole with the penny washer sqeeezing the rubber tight. It stayed like that till I scrapped the car.

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bizzard Veteran II

bizzard

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Posted

Another sensible solution is to stick Swan Vestas matchsticks in the holes, red strikers on the outside which will strike and burst into flames when coming alongside anything abrasive and warn you.

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