New Cherub Owner! Help with repair technique

[stom]

Hi All,

I'm now the proud new owner of 2654, having just made the long trip to Newcastle to collect her.  She needs a bit of tidying up in a few places, however an area I need a bit of advice on is the best way to repair this crack in her side tank....


IMGP5577 by stom tom, on Flickr

I know she's a Kevlar boat and will be very careful not to sand back to the fibres.  I've also got access to  a sand blaster if that would help with carefully removing the layers of paint and resin. 

My current thinking to repair involves carefully removing the paint and resin and then laminating layers of carbon/glass over the top. Then sand back the repair to flush and repaint.  Is it this simple or is further work required/advised?

[kokopelli]

hi Stom,
It maybe very similar to Sweet Dreamzzz build; Carbon kevlar foam sandwich. if so it is pretty bullitproof. I guess it is very stiff and you cannot push the cracked area in very much. If so;
First thing is not to worry everything can be put right really easily. If not sure just sand and patch with layer of epoxy and carbon or glass cloth for a quick repair, or even a fillet of epoxy bodge (international waterite) would do the trick so to get you sailing PDQ. hope to see you at Carsington on Sat. BFN. ade.

[stom]

Thanks Ade!  It's not going to put me off going to Carsington!  I can't wait to get her on the water.  I'll make a rough repair for the time being and lok to do something more permanent over the winter.

[roland_trim]

I think that is a crack between floor and side tanks.

1) For now sail it. From playing around with the boat in the rugby club the cracks do'nt open with tension or when trying to twist the hull. Gaffa or side tank bungs out the back will work for the first few sails.

2) For a full repair look out for the sticky weekend? There will be plenty more experienced than me to help with the options. I'd take advice form the people who know the boat, but it may be less painful to make the side tanks more "hiking supprts" than water tight (i.e. cut proper drainage and leave).

3) Patrick and Andy L  aer both still around on this forum. Patrick built her and Andy has sailed her. That crack may have been there for a while.

[Phil Alderson]

Thanks Ade!  It's not going to put me off going to Carsington!  I can't wait to get her on the water.  I'll make a rough repair for the time being and lok to do something more permanent over the winter.

Stom,
watch out about temp repairs, they have a habit of becoming permanent repairs. Particularly with a Kevlar boat each time you sand into the structure you will increase the footprint of the repair.

First establish how bad the crack is: Does the side tank leak through it? Can you flex the area (floor and tank) and make the crack open and close? If it is close to the shrouds does the crack open with rig tension (bounce on the forestay while someone has a finger on the crack)
If the results of all this are OK, then it is probably cosmetic and can wait till the winter. Draw on the end of the crack with a permanent marker so you know if it is growing.


If you to find problems with the above tests then it needs to be fixed. Investigate and find the problem, a stanly knife is good cut through the laminate on the open side of the crack and find out what is there. There is a good chance that when it was built the panels were probably assembled with a filet, and then tape put over the joint. It looks a bit like that filet and tape joint has cracked away from the panel. That broken joint needs to be removed, a patch over the top will be hard to seal. By cutting away with a knife and chisel you can probably get the broken stuff off without exposing too much kevlar.

[stom]

Thanks for the advice!  I can hardly flex the crack when i push on the surrounding area, so hopefully can deal with it over winter.  She'll get a layer of gaffer tape over her next week, so i can sail her at Carsington.  I'll certainly look for the next sticky weekend.

Does anyone know if you can still pay the class association joining fees by paypal, or is it now only cheque or bank transfer?

Thanks again for all the advice.  Looking forward to meet some more experienced Cherub owners.

Tom

[Hayley_Trim]

Cheque or bank transfer Tom. Paypal unfortunately not available.
The boat looked good when I saw her a few weeks ago. Hope you get a nice breeze at Carsington next week. Sorry we won't be there.

[stom]

A long time in the making however... a quick update after all the helpful advice i've been given! I've spend some time repairing the cracks in both of the tanks(cut out the damaged areas & replaced with new foam & carbon).  I've also added in some steps/kick bars to help my crew get out onto the trapeze.  Finally the kicker & downhaul have been moved out to the gunwales and the kite has been made into a single line system(removing the redundant castle in the process).  There's also a new rudder & stock thats nearly complete.

Does anyone have any ideas for a budget spinnaker sock?  The kite's not going to work single line without one.

[roland_trim]

Free material is available from royal mail. Ask at a post office for some mail bags with holes on.

Others have had success stitching trampoline fabric together.

[roland_trim]

Ps with the boat looking that good, are you sure we can't temp you to bunk for a couple of days down in Babbacoombe? You'll both love it...

[Hayley_Trim]

Boat looks great, well done!
If you can spend a little bit on the sock it's well worth talking to Kate Noyce at Bearfoot design. She's very familiar with cherubs and extremely nifty with a sewing machine. 

[stom]

Ps with the boat looking that good, are you sure we can't temp you to bunk for a couple of days down in Babbacoombe? You'll both love it...

 
I may have a plan I'll discuss it with you when I come down to Bristol...

[phil_kirk]

Nice work. 

We made our lkite sock.  The black trampoline mesh is similar to what is used on the RS classes.  The cloth tend to fray when cut so needs to be sealed along the cut edges before  being stiched together.  Try cutting with a hot knife if possible. Becuase the cut edges are quite sharp and tend to catch on everything it is necesary to edge each join with centrefold fabric tape stiching it on.  It is best to make a sock with four panels so it is rectangular in section.  This holds the sides appart and reduces the friction on the kite during hoists and drops.