Bringing the curve up from to bottom heh,.....
Where did your inspiration come from?
Good job, but not the first time it's been done
Good Job Shifu - I am watching your progress as I would love to try it one day!
You might get a few boards being left at your door step with "Please fix" on it.
Gives you something to do on the many windless days!
I thought I would resuscitate this thread with some info on how this repair turned out.
After I took the wedge out of the nose I hot glued some blocks of styrofoam around the perimeter. I then shaped these to the rough profile I wanted and slathered epoxy and microsphere mix all over it. A bit of shaping and refilling took place using a rasp, sandpaper and scraper. I also sanded back the surrounding paint so I could get good adhesion for the new glass layers. Hot gluing worked, but it is easy to melt the styro, so I squirted the glue onto a stick and waited a few seconds before applying it.
When I was happy with the shape I laid glass on in small pieces about 100x20mm in a fan pattern all around the nose. Strips of builder’s plastic were taped over this to squeeze the glass down. This forced out excess resin and stopped gravity pulling the glass away from the underside. Two layers of glass were put on in two stages. There is an extra semicircular piece laid over the top of the nose as extra impact reinforcement.
After pulling off the plastic and tape it was pleasing to see that the glass had been pressed down tightly against the board. There were no air bubbles that I could see. In the pictures you can see the pattern left by the plastic strips and this required a bit of sanding back but not a great deal.
For the moment the nose is being left un-faired and painted as I needed to get it out of the shed and the owner wants to have it on standby to sail again (should we ever need a 78 litre wave board in SEQ). The Epoxy is UV stabilised so fairing and painting can wait indefinitely.
Select to expand quoteShifu said..
I thought I would resuscitate this thread with some info on how this repair turned out.
After I took the wedge out of the nose I hot glued some blocks of styrofoam around the perimeter. I then shaped these to the rough profile I wanted and slathered epoxy and microsphere mix all over it. A bit of shaping and refilling took place using a rasp, sandpaper and scraper. I also sanded back the surrounding paint so I could get good adhesion for the new glass layers. Hot gluing worked, but it is easy to melt the styro, so I squirted the glue onto a stick and waited a few seconds before applying it.
When I was happy with the shape I laid glass on in small pieces about 100x20mm in a fan pattern all around the nose. Strips of builder’s plastic were taped over this to squeeze the glass down. This forced out excess resin and stopped gravity pulling the glass away from the underside. Two layers of glass were put on in two stages. There is an extra semicircular piece laid over the top of the nose as extra impact reinforcement.
After pulling off the plastic and tape it was pleasing to see that the glass had been pressed down tightly against the board. There were no air bubbles that I could see. In the pictures you can see the pattern left by the plastic strips and this required a bit of sanding back but not a great deal.
For the moment the nose is being left un-faired and painted as I needed to get it out of the shed and the owner wants to have it on standby to sail again (should we ever need a 78 litre wave board in SEQ). The Epoxy is UV stabilised so fairing and painting can wait indefinitely.
Amazing, this is the first time I have seen this thread.
And THANKS Ian, for helping get this back on the water!!!
From
The Owner
Yep, looks great but I think if you only have 3 layers of glass over soft foam, it's going to be a bit vulnerable.
Well done nice job. A saw that I use for cuts into foam is a Japanese pull saw that's designed for cutting timber plugs. It only has a kerf on one side so a very very fine cut
Select to expand quotedecrepit said..
Yep, looks great but I think if you only have 3 layers of glass over soft foam, it's going to be a bit vulnerable.
I agree. My first attempt at this I used extruded polyurethane (as it is waterproof), and after I had it all sanded and finished, I realised that it flexes and the glass doesn't. Maybe styrofoam will be less flexy, but still not waterproof.
For the second attempt I glued 8mm thick divinycell around it, and added enough layers to give me the shape I needed.
Select to expand quoteFormulaNova said..
decrepit said..
Yep, looks great but I think if you only have 3 layers of glass over soft foam, it's going to be a bit vulnerable.
I agree. My first attempt at this I used extruded polyurethane (as it is waterproof), and after I had it all sanded and finished, I realised that it flexes and the glass doesn't. Maybe styrofoam will be less flexy, but still not waterproof.
For the second attempt I glued 8mm thick divinycell around it, and added enough layers to give me the shape I needed.
I am interested in these views about the strength of the new nose. The glass was laid on in 20mm wide strips each overlapping the other, so in each of the two applications of glass there are extended areas that are two layers thick. This combined with the single top piece means that significant portions of the new nose are 4-5 layers thick. This said I do take the point that it might have been better with more glass. We will have to wait and see. The owner stopped going over the front long ago (unless he hits a eagle ray) so I don't expect the nose will have to cope with too many beltings. Also this 78 litre board will be lucky to get used about four times per year so the probability is it will remain unscathed. Time will tell!
Mast impact should still be on the old sandwich section, and 4 to 5 layers may be enough over the new foam. Part of the foam protection is the stiffness of the covering.
A 3mm sandwich of 1 layer of 4oz glass, 3mm 80kg/m2, and another 4 layers of 4oz glass, + a 6oz layer of carbon kevlar, is what most of my boards have on the nose, and they aren't bullet proof.
5 layers of cloth is much thinner than this, so no where near as stiff, (I have this idea in the back of my head, that stiffness varies with the square of thickness). So any head on impact is going to compress the foam at point of impact, because the skin isn't stiff enough to spread the load far enough. This is likely to cause a failure of the outside skin. If the skin is stiffer it leads to a more localised failure of the outer layers of cloth, easier to fix and more likely to stay waterproof.
