That loud green paint's all going to have to come off...

[Greenheart]

Better...to repair on the inside with resin and glass mat.

Would a stronger repair be possible if I made the crack wide enough to suspend a small bit of plating below it? I could inject glassfibre paste through the crack, pull the plate up to squish the paste almost flat, then spread more paste in the visible damage above...so the mended area would be stronger than the undamaged surrounding...

...wouldn't it?

 

[VicS]

Would a stronger repair be possible if I made the crack wide enough to suspend a small bit of plating below it? I could inject glassfibre paste through the crack, pull the plate up to squish the paste almost flat, then spread more paste in the visible damage above...so the mended area would be stronger than the undamaged surrounding...

...wouldn't it?

If we are talking about the crack in the side deck where it meets the aft deck

I think my preferred method would be to consider another inspection hatch to give access and then patch with resin and glass ( tape might be more convenient than mat ) from the inside of the buoyancy tank. Several layers would make it water tight and good and strong without damaging the visible parts.

 

[Greenheart]

If we are talking about the crack in the side deck where it meets the aft deck...consider another inspection hatch to give access and then patch with resin and glass.

Thanks Vic, why didn't I think of that?

 

[VicS]

Thanks Vic, why didn't I think of that?

You'll have to clean it up thoroughly ( acetone ???) cos the back side of GRP seems to go funny and sticky and roughen it with the coarsest grade of aluminium oxide paper.

use a torch and mirror through one of the existing inspection hatches to be sure you can get at what want to before cutting another hole.

 

[Greenheart]

You'll have to clean it up thoroughly ( acetone ???) cos the back side of GRP seems to go funny and sticky and roughen it with the coarsest grade of aluminium oxide paper.

use a torch and mirror through one of the existing inspection hatches to be sure you can get at what want to before cutting another hole.

Thanks...access is a concern...there's the sound of water sloshing up and down inside the side-decks...not very much perhaps, but it can't be drained using the bung, so who knows where exactly it is...I begin to think there's more than one level to the internals...so putting a 5" hole in the bulkhead mightn't aid access!

But I've just ordered the hatches; I think that remains the best plan. Maybe I should reinforce the hatch-hole with a square of ply, rather than weaken the bulkhead?

Not so sure about the underside of the glassfibre having a sticky surface...the underside of my panels often seem to be just the fluffy strands. I wonder if I can still use the Glass Fibre Paste I already bought, on a surface which isn't itself hard and solid?

Was acetone a joke? There's loads here, SWMBO has given up on tarty fingernails...I quite liked 'em, but she did let them get chipped & scratched, so better without.

 

[VicS]

Thanks...access is a concern...there's the sound of water sloshing up and down inside the side-decks...not very much perhaps, but it can't be drained using the bung, so who knows where exactly it is...I begin to think there's more than one level to the internals...so putting a 5" hole in the bulkhead mightn't aid access!

But I've just ordered the hatches; I think that remains the best plan. Maybe I should reinforce the hatch-hole with a square of ply, rather than weaken the bulkhead?

Not so sure about the underside of the glassfibre having a sticky surface...the underside of my panels often seem to be just the fluffy strands. I wonder if I can still use the Glass Fibre Paste I already bought, on a surface which isn't itself hard and solid?

Was acetone a joke? There's loads here, SWMBO has given up on tarty fingernails...I quite liked 'em, but she did let them get chipped & scratched, so better without.

No acetone was not a joke. You'll find it with the glass fibre repair stuff in chandlers. I've just bought a can of it from Eastcoast fibreglass supplies along with other stuff I need. Nail varnish remover may not be acetone or may contain other (oily) things even if it is.

 

[Bilgediver]

I have no information on leaks in the other one.

Any problems there then go to Boots!

 

[Greenheart]

Nail varnish remover may not be acetone or may contain other (oily) things even if it is.

Thanks. Any idea whether Glass Fibre Paste, which incorporates the fibrous matting, will adhere beneficially to rough, fluffy old GRP? I suspect not...so (I'm guessing) it'll need scraping back to the hard underlying structure, of which there is not much, in my thin ancient decks.

I'm hoping a few thin layers of the paste, over both sides of the split, applied both above and below, will strengthen the damaged area without adding unwelcome kilos.

 

[Greenheart]

I found a hole...so I'll make another...

Gently parking my weight on the sidedeck where I'd found cracks, I saw them broaden frighteningly. So I'm sure the repair needs doing, pronto.

I scraped off some of the green awfulness, and discovered that the crack running along the sidedeck-overhang, turns through a 90º curve to meet the other crack, running starboard to port, between the sidedeck and rear deck.

I'm guessing that some internal structure follows that curve, so when the deck was overburdened, the grp cracked along that line.

The only way to repair that area from below, must be by cutting a new inspection hatch in the cockpit-bulkhead adjacent...hence I've bought some...

View attachment 31619

...but having established that the decking isn't amazingly thick & strong, I'm slightly hesitant about cutting a ruddy great hole in a perfectly sound section!

Would I be wise to reinforce the area round the inspection hatch with 4mm ply, glued to the inside of the GRP? It wouldn't be difficult, or add much weight.

How on earth do I get rid of the "attached thumbnail", below? I didn't ask for it to appear.

 

[cliveshelton]

The Plastic Padding is the same.

I'll shut up on the matter now. I'll just mention that Searush sailed his Solo(which became mine) with this crack in the hull for years.

Actually there's a product which will deal with both cracks!!

tee hee.

 

[Greenheart]

Actually there's a product which will deal with both cracks!!

"Also available in Oprah-size!"

 

[Greenheart]

Can anybody tell me how smooth or abraded the old glassfibre surface will need to be, before I start reinforcing it with mat & resin? Does new resin assimilate strongly with the old GRP to make a solid bond, or does it need some rough uneven structure, like proud screwheads, to set around?

Despite earlier plans, I'm hoping to avoid cutting new inspection hatch holes...so I'm hoping a thin new layer of mat/resin laid on top, will hold the split deck together.

If that fails, I'll revert to Sikaflex and 4mm ply, over the afflicted area.

 

[prv]

Can anybody tell me how smooth or abraded the old glassfibre surface will need to be, before I start reinforcing it with mat & resin?

Attack it with an angle-grinder is the usual advice. I generally use either a wire brush wheel in a drill or 40-grit sandpaper. I don't think you need to stud it with bolt heads!

Pete

 

[Greenheart]

Attack it with an angle-grinder is the usual advice.

Thanks...although I'm out of range of a power supply.

Embarrassing pic:

View attachment 31779

As well as scratching off the green, I tried to roughen the smooth grey of the glass beneath. Not sure if that's a suitably-abraded surface for adding new resin & mat to?

I'll aim at eventually having the deck re-covered, so the unevenness of the repair won't be a big deal. I just want it safe and watertight. Can you see anything that'll prevent reinforcement by new layers of matt & resin, from achieving that?

 

[prv]

I just want it safe and watertight. Can you see anything that'll prevent reinforcement by new layers of matt & resin, from achieving that?

Only that I would have expected a wider tapered/abraded area - but perhaps that's because I'm used to thicker GRP on yachts rather than dinghies.

Also that you have previously mentioned using body filler instead of proper mat and resin, but I'm not sure that's still what you have in mind.

Pete

 

[Greenheart]

...you have previously mentioned using body filler instead of proper mat and resin, but I'm not sure that's still what you have in mind.

If I can find the receipt, I'll take the Glass Fibre Paste back, and switch it for a matt/resin repair kit instead. For thin decking damage like this, there's really no hole to fill...

...and, thanks; I had it in mind to broaden the scraped area.

I'm hoping adding a layer or two of matting is effectively thickening the original lay-up? And as such, aside from adding a little weight, the only effect is added strength?

I'm unnerved by my own cowardly decision to turn back from the bold plan of internal structural reinforcement.

 

[VicS]

Roughen it with the coarsest grade of aluminium oxide paper you can find in the DIY store..... P60, or even P80, shuld do the job.

Dont use a power tool, esp an angle grinder, on something so thin or you'll have nothing to repair before you can say, "whoops."

Use liquid resin and glass tape. 1" wide might be wide enough. 1.5" if you can find some ( 2" if you feel its necessary)

put on two layers, in one go. Be sure to saturate the tape.

sand off the edges a bit when cured and apply another coat of resin .

Tape is easier to use than CS mat. It does not fall apart while you are working.

For a stronger bond to the substrate you could use epoxy resin. Tape is compatible with epoxy resin


Work quickly or choose a coolish day. Dont hold the pot of mixed resin in your warm hand, or it will suddenly get hot and set solid ( It happens to almost every body!)

( dont drop resin on the cat or dog)

 

[Greenheart]

Sounds like invaluable advice, many thanks Vic. To be honest I get a bit bewildered in the chandlery...are there brand-names you recommend, for the tape & epoxy resin?

Must the resin be used in one go, once it is opened?

 

[VicS]

Sounds like invaluable advice, many thanks Vic. To be honest I get a bit bewildered in the chandlery...are there brand-names you recommend, for the tape & epoxy resin?

Must the resin be used in one go, once it is opened?

Tape is tape I think The usual weight for repairs etc is 200g, if offered a choice.

( example that comes up on my computer easily because I just ordered a load of stuff from them http://www.ecfibreglasssupplies.co.uk/p-1775-fibreglass-tape-200g-x-25mm.aspx )

Polyester resin has a shelf life that is not all that long..... Epoxy is much longer. Epoxy must be mixed accurately and is more expensive so there are downsides. With polyester resin the "hardener" is only a catalyst so mixing ratio not critical. Both have pot lives of only a few minutes when mixed.

Main choice of Epoxy is between Wessex resins and SP resins. I choose Wessex because with the fast hardener it can be used down to 5C. SP is apparently too thick to use below 15C. ( If I dont get the planned job done soon i might regret that decision!)

I think Id just use polyester on your job. Epoxy for mine for maximum strength. If my job fails the boat will sink!

 

[Greenheart]

Thanks again, Vic. Best of luck with your own repairs.

I'll report back & photo my work for the public amusement. I can imagine glueing myself to the boat, late on a Saturday evening, two feet out of reach from my phone.