GRP repairs

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Iain_H

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Following on from this month's PBO article on GRP repairs. I've got the smallest hole on my deck...right on the curve from the deck going over to starboard; at the cockpit. I would estimate 1cm wide and 3/4 cm width.

Do I still need a backing plate for this job or is there a simpler way to tackle this?
 
No, just fill it with gel coat filler. Wait for it to go hard properly, this could take a couple of weeks. Then using a fine wet and dry rub down, then use G3 and finally polish off.

Barry
 
I confirm. A hole. Right through the deck. Looked like I would need fibreglass. Would I get away with a filler (glass bubbles); would I ideally need to use a backing plate.

Such rapid response guys!
 
As it is a pretty small hole I'd proceed as follows:

V out/ chamfer the outside edge.
Clean it all out with acetone.
Seal the inside with brown packing tape, preferably shiney side to the repair.

Fill up the hole with epoxy, thickened with collodial sillica and micorfibres. Remember to leave the finished surface a bit lower to allow for the gel coat.

After curing de-wax the epoxy with a dab of acetone. Oh, you can remove the tape at this stage, as it is only there to stop the wet epoxy sagging.

Fill the remainder with a suitably matching gel goat. After curing, sand down, burnish and finally polish.

Finally, open a beer, stand back and admire your work.
 
I would - if possible to get to underside ....

get a small plate of plastic ... nice flexi stuff with glossy surface. Wrap it in smoothed out cling-film.

Next clean and rough up the underside around and in the hole and above as well ..... chamfer both sides of hole if poss.

Mix up a chopped strand mix of GRP and resin ... nice blob of it and place central on the plastic plate .....

Press up into the hole and wedge the plate into place ..... making sure that the blob is squeezed well up into the hole .... if you can get the plate really faired with the surround excellent.

Now on top ... check to see the resin blob has filled the hole ... you could help this with a thin stick or blade ... If it's exceeded the size of hole and now proud ... remove a bit to just be under the top level of the hole ... leaving a small "dent".

Leave to partially set ... now fill in with micro-balloons and resin to bond to the already inserted blob from below.

Leave all to set hard.

Sand back top filled section to fair of. As you used cling-film under on the card .. you can now remove the card and have a reasonable finish under as well.

This repair is reasonably strong - but is not designed to be structural strength ... if that is needed then you need chopped strand mat in the resin under to fair out a GRP patch.

FYI - Pre-mixed GRP Chopped strand and resin can be bought from GRP suppliers or local "serious" model shops .... its like a hairy paste !! Just add hardener ... its amazing stuff.
 
you cant you expect filler to hold with no backing... its filler after all! If its this small...First mask of the area with tape or whatever..Dont be afraid to open the hole a little bit to make it more workable. Wet the back of the hole with resin, stuff some resin soaked fibreglass cloth (not matting-it will fall to bits) into the hole and pull it back out a bit so its contacting the back and sides of the hole. Let it go off, yank it about to be sure its got a good hold,, if not just do it again. Sand back below the surface and then fill.
A dremel type tool is a real boon, to be honest- probably get a cheapo from BQ. trick is.. dont be afraid of resin and fibreglass and-dont mess about with keyhole BUPA surgery! as a skill level for a small hole.. well if you can spread butter on your toast,,, thats about it! You ll wonder what the mystique was about!
 
G'day Iain,

You said:
<<I've got the smallest hole on my deck on the curve from the deck going over to starboard; at the cockpit. I would estimate 1cm wide and 3/4 cm width>>

That's about 10 mm long and only 7 mm wide, about the size hole you would expect from a screw driver impact. So we are not talking major structural deck damage, but rather a small leak point.

All you need is an egg cup of resin and a few drips of catalyst, half an egg cup of Gorilla hair More commonly known as Micro-Fibres and the same amount of Micro-Balloons or "Q" Cells or Micro-Sphears. an empty butter container or two and some latex rubber disposable gloves.

Borrow a drill or plunge router and make a neat round depression at about 15 degrees from the top and the bottom. it should be about 12 mm across, just enough to give a clean surface all round the damaged area.

Clean the area and mask around the hole on deck, three layers deep, this avoid any clean up later and leave the top proud for sanding.
Cut a ring of plastic from the butter container lid about the size of a 2 bob bit and tape it below the hole, then place a wad of rag on the end of a stick and wedge it between the floor and the plastic ring to prop it in place, it should deform a little and press up into the hole a bit, this is OK.

From the top:
mix a very small batch or resin, about half a thimble full , add on drop of catalyst and mix in a clean butter container, add some balloons to form a loose paste that just flows, not stiff, put a tiny bit down the hole to cover the plastic, 1 or 2 mm deep is enough.

Now mix another small batch the same size and mix some Micro-fibres to a paste about as thick as toothpaste, lay this over the wet balloons, try not to mix them too much, use a very small screw driver to work it in and make sure you get no air trapped. Build it up till you are about 5 mm from deck finish. Now get the rest of the balloons you mixed first and smooth them over the top, if you put 3 layers of tape around the hole and level the balloons to that, you will have enough to sand it smooth after it cures.

To finish the underside: After curing, remove the prop, rag and ring of plastic, sand off any high spots (if any) and fill with Micro Balloons, use an old plastic ruler to follow the contour, and sand when cured.

If the topsides has a non slip pattern and you want to make an (Almost) invisible repair, let me know, there are a couple of ways to this.

Avagoodweekend......
 
[ QUOTE ]

G'day Iain,


If the topsides has a non slip pattern and you want to make an (Almost) invisible repair, let me know, there are a couple of ways to this.

how is this done? i'd be interested to know this thanks
Avagoodweekend......

[/ QUOTE ]
 
get a lump of plasticine and push it onto a good bit of deck. This will make a smashing mold when you push it in to the wet filler on your repair....

hows 'at!
 
i never thought of that,i have some old screw holes to repair on my non-slip deck i will give it a try cheers dog watch.
 
I can't thank all you guys enough. Over and over. So many good replies in here. Love the plasticine idea right at the end. But for sheer amount of effort in the reply, I have to go for the butter holder. Sounds like work but a good finish....

Cheers again guys!
 
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