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Nose crunch - repairs

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Created by ejmack > 9 months ago, 12 Apr 2009
ejmack
VIC, 1308 posts
12 Apr 2009 7:00PM
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I recently "crunched" the front of my board.... yet again. I thought to myself " this is getting expensive" so decided to give the repair a go myself. Sanded back the damaged area and some, removed all damaged glass, etc. Re glassed the area with 2 layers of cloth and resin. I now have the new repair nicely sanded back and ready for the next stage. Problem is, I'm not sure how to proceed here. According to the Board Lady website, a Epoxy fairing compound is applied and sanded. Then an Epoxy primer and eventually a paint. The problem is, where do I get this stuff, is it called the same in Australia and what type of paint do I use? Any help would be greatly appreciated!

FormulaNova
WA, 15086 posts
12 Apr 2009 6:10PM
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I generally use epi-fil which you can get from Whitworths. It is a two part epoxy paste, and I imagine it is the same as what she refers to as fairing compound.

As far as paint goes I have just used whatever I could get that matches the colour of the board, and is usually just a spray acrylic.

decrepit
WA, 12774 posts
12 Apr 2009 6:34PM
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For "bog" I just add a filler powder to the resin (I hope it's epoxy you used).
There's several types of powder, "Qcells", "micro balls" etc.
Who ever sold you the resin should have something like that.
As far as paint goes, auto motive spray can stuff is the easiest, but not all that durable.
I use two pack urethane for big jobs, but that's expensive if you're just doing the nose.

Oh, and if you crunch it again, try and find some carbon-kevlar 200gm cloth, put that under a layer of glass, then you shouldn't have as much trouble. But what ever you do don't sand into the kevlar, (that's why you put it under a layer of cloth). It goes furry, and makes finishing a night mare.

ejmack
VIC, 1308 posts
12 Apr 2009 11:06PM
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Cheers guys!

I used Solid Bond 330 resin and suitable catalyst. Where would be the best place to purchase carbon-kevlar 200gm cloth?

Thanks again for the tips!

decrepit
WA, 12774 posts
12 Apr 2009 9:14PM
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Being in WA my sources aren't much good to you.
But you could try high tech kayak builders, you don't need much, wholesalers are only going to sell it by the metre, (@ about $90 per metre last time I looked) all you need is offcuts.
Talking about cutting, kevlar is supper tough, try your wife's pinking shears, then don't let on when she says they've suddenly gone blunt.

Bondalucci
VIC, 1579 posts
12 Apr 2009 11:52PM
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Evan, sorry to hear you've done it again.... Presumably the Futura????

What is hitting the nose? The mast or the boom? If it's the mast, you should look at getting a "deviator" that goes around your mast base and deflects the mast to miss the nose of the board during a catapult. I've got one lying around you are welcome to borrow for a while.

As for the repair... no need to overcomplicate it.
1.Seal it with epoxy resin (include glass for strength depending on how severe it is)
2.Sand it roughly to allow next coat to adhere
3.Finish with polyester resin (which is much easier to sand smooth to a nice finish)
4.Mask off the blue area and spray using white care duco fading it along the white rail so it blends without any seams, then lightly sand with super fine wet'n dry
-job done!

(if you've dinged into the blue area this time, it means it's a bit harder to colour match the repair, but with patience, masking and colour matching it'll still look great.
Good luck.

decrepit
WA, 12774 posts
12 Apr 2009 9:59PM
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Bondy, putting polyester on top of uncured epoxy is a no no, I forget which way it is, but at least one of them won't cure properly. You can only mix the 2 if the one underneath is totally cured, ie 2 or 3 weeks at room temp, or a day or so at 50C.
And I disagree about polyester being easier to sand.
Polyester sets much harder than epoxy, and if you don't get to it within about 30hrs, is very hard work.
I use "Bote Kote" epoxy, and it's very easy to sand, as long as you don't try too early, overnight in summer is enough but a good 24 hrs is better in winter. Add some filler to it and it's even easier, not to mention lighter.

keef
NSW, 2016 posts
13 Apr 2009 12:16AM
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decrepit said...

Bondy, putting polyester on top of uncured epoxy is a no no, I forget which way it is, but at least one of them won't cure properly. You can only mix the 2 if the one underneath is totally cured, ie 2 or 3 weeks at room temp, or a day or so at 50C.


polyester wont bond to epoxy, but epoxy will bond to polyester and will bond too most things except plastic

Bondalucci
VIC, 1579 posts
13 Apr 2009 12:17AM
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Decrepit,
I've done it heaps of times (polyester over epoxy that is!!!!) and never had a problem. I make sure the epoxy layer is cured, but that is only 24-48 hours (sunny Victoria).
I think it was Keef who reckoned it wouldn't adhere well enough, but if you rough it up it works fine.




I agree if it was around the foot straps or mast base it might be an issue due to the loading and flex the board may come under, but for a nose repair mine are stronger than before the operations.

decrepit
WA, 12774 posts
12 Apr 2009 10:26PM
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As I said I can't remember which way round it is, but I tried it on a fin a while ago, and I just had a sticky mess, even after several weeks, when I asked our resident guru, he said that's what happens when with a polyester, epoxy mix. The fumes given off by the uncured under resin stops the top coat going off properly.
You're right about sanding it to make a good bond though.

keef
NSW, 2016 posts
13 Apr 2009 6:48AM
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Bondalucci said...


Decrepit,
I've done it heaps of times (polyester over epoxy that is!!!!) and never had a problem. I make sure the epoxy layer is cured, but that is only 24-48 hours (sunny Victoria).
I think it was Keef who reckoned it wouldn't adhere well enough, but if you rough it up it works fine.


I agree if it was around the foot straps or mast base it might be an issue due to the loading and flex the board may come under, but for a nose repair mine are stronger than before the operations.

let me rephrase that Bondalucci polyester will stick to epoxy but its not recomended, what happens is you get it to stick but not a bond and in time the moisture will work its way between the layers the best thing to do is if your working with polyester then repair with it and vice virser, but haveing said that you can get a spray addhesive primer that you spray on plastic car bumper, its used so the paint doesnt peel so maybe that could work


ejmack
VIC, 1308 posts
13 Apr 2009 10:47AM
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Bondalucci said...

Evan, sorry to hear you've done it again.... Presumably the Futura????

What is hitting the nose? The mast or the boom? If it's the mast, you should look at getting a "deviator" that goes around your mast base and deflects the mast to miss the nose of the board during a catapult. I've got one lying around you are welcome to borrow for a while.



Hey Bondi. Yep, the Futura again The mast on the nose yet again. Although, in my defence, I was cut off by another windsurfer, but I wont go there..... other than to say Inverloch's (the pond) just too small an area on a good day!

In short, the damage wasn't too bad but I thought it required a bit of work. It didn't effect the bottom surface thank fully, or at least, I can't see or feel any damage to the bottom. Matching the blue would be a pain I'd imagine!

I do have one of those rubber "knob" things. Is the deviator the same? I found mine quite useless as it takes up most of the mast track and I can't position the base in my normal position. Really appreciate the offer however... and cheers for the tips on repairs!!!

Just about finished now besides the paint but all the advice will be appreciated eve nmore so after my next mishapp. Cheers all!

Mark _australia
WA, 23468 posts
13 Apr 2009 10:04AM
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Keef I can't see plastic primer working as it is designed to melt the plastic a little to get the paint to stick. Resin is totally different

keef
NSW, 2016 posts
13 Apr 2009 4:16PM
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Mark _australia said...

Keef I can't see plastic primer working as it is designed to melt the plastic a little to get the paint to stick. Resin is totally different

thanks for the tip mark ,i have taxi cabs and were allways useing that stuff on bumpers to me it smells like contact addhesive, but ill take your advise and use it on bumpers only

NasiGoreng
VIC, 260 posts
13 Apr 2009 7:34PM
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interesting thread guys,

ive been confused about the difference in epoxy/ poly resins for ages !!

THANKS !



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