Sea Kayak Repairs - Opinions Required!^

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mitchmix99
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Sea Kayak Repairs - Opinions Required!^

Post by mitchmix99 » Sun Dec 31, 2006 4:45 pm

I picked up a Nordkapp Jubilee in October and am working on it over the winter. I have 2 areas of work on the boat to do and was looking for opinions on how I should go about doing it.

The first is the foot pump pipe and attached strum box are not centre and have not been glassed in very well (see pics). I’m looking to take this install out and put a new strum box and pipe in, hopefully in the centre under the seat. I’m not sure how is best getting the old fibreglass out – do I chisel around it and see if it comes away easily or do I sand it down and glass over the top and accept I’m going to have a bit of a lump there? Any suggestions would be great.

http://www.ibcsl.co.uk/kayak/pump1.jpg
http://www.ibcsl.co.uk/kayak/pump2.jpg

The second bit of work is the seam – there are areas where there is damage that goes down to the gelcoat. What I was looking to do is gelcoat in the damaged area, then paint the entire seem a fresh coat of black paint. At each end of the boat there is more wear on the seam so I may glass in some new fibreglass tape before painting. Again any suggestions on this would be great.

http://www.ibcsl.co.uk/kayak/seam1.jpg
http://www.ibcsl.co.uk/kayak/seam2.jpg

I've read the almanac and was hoping for a bit more help!
Anything would be most appreciated!!

Thanks

mitchmix99

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MikeB
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Post by MikeB » Sun Dec 31, 2006 6:54 pm

Hmmm - if you're lucky, something like a wallpaper scraper just might slip it off. Failing that, I guess you might be into something like a Sureform used carefully and sandpaper.

If you use woven g/f tape to cover up any damage it'll look ok - try and avoid ordinary mat.

For the new s/box fitting, I guess you've found this pic in the Outfitting article? Just a suggestion.

Image

Now to the gelcoat damage - don't think about painting the black strip. It'll work of course, but it's going to get scratched / rubbed off easily. That strip is gelcoat which has been thickened with filler powder and coloured with colourant. If you have a proper g/fibre place nearby you'll be able to get all the stuff from them.

Pics / progress reports would be nice - - -

PeteB
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Post by PeteB » Sun Dec 31, 2006 8:48 pm

and just to add to Mike's last point about the gel coat, you'll need to add a special waxy additive which stops the gel coat from remaining tacky (normally gel only goes hard on the non air exposed side so that the lay up resin bonds to it during the laminating process - on the outside seam you need this additive to force a full cure in the presence of air)

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Jim
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Post by Jim » Mon Jan 01, 2007 9:54 pm

That strum box looks to have been so badly laminated in I would attempt to prise it away with a chisel first - the redness around it suggests it's polyester resin which doesn't stick well to epoxy unless you give it a good mechanical key, since it appears to be a cowboy job I wouldn't expect the fitter to have bothered too much about that. If that sort of works you could also try very gently warming it with a paint stripper, waft the heat around and use the bare minimum lest it should affect the laminate of the boat below. If all that fails sanding is the way forward, a sanding disc on an angle grinder used extremely judisciously can be a quick and easy solution.

Jim

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mitchmix99
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Post by mitchmix99 » Tue Jan 02, 2007 2:00 pm

Strum box was indeed badly laminated - the chisel has got it off and i've started work on getting the remainder of the fiberglass off - first using the chisel then i think some sandpaper. I'm not sure how well it will look after sanding - i'll upload a picture once complete and verdicts can be reached. I was thinking of glassing over the effected area after to give it a better finish. I was thinking of putting the strumbox under the seat but on my boat the seat is glassed in. This would only really leave the original location as the place to glass in a strum box, i would make it more central than the old install but depending on how the removal of the old glass this may not be possible.

Should have some pics up tomorrow night!

cheers

mitchmix99

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mitchmix99
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Post by mitchmix99 » Wed Jan 03, 2007 7:34 pm

Here's the pics - more sanding need to get the rest of the old fiberglass out. Some comes off easier than others. I've noticed that the top layer of original glass is a little rough now in places and some of the woven glass is showing. I guess I will have more of this as i uncover the rest of the old weld. I guess my only option is to add a layer of woven over the "scruffy area" to make it look tidy? I'm thinking of re-installing a new strum box more central as the seat is glassed in. I can tidy the complete area up when doing this. I think i'm also likely to glass D rings in, as per the almanac - i can always get the strum box out then if required.

Any thoughts?

http://www.ibcsl.co.uk/kayak/boat1.jpg
http://www.ibcsl.co.uk/kayak/boat2.jpg
http://www.ibcsl.co.uk/kayak/boat3.jpg

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Jim
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Post by Jim » Wed Jan 03, 2007 9:00 pm

Looks like a good plan to me.

you want to try and get the strum box in the lowest part of the boat if possible, this is probably under the seat (in which case not possible) so you want to get as close as you can.

Do sand back all that rubbish and laminate a piece of woven glassfibre or glassfibre tape on top of it to restore any damage you may have done when sanding, but try and do the bare minimum since thickening in this area is not ideal if it's where you want the strum box. I'd suggest a small repair pack of epoxy resin and some glassfibre tape from a chandlers - it won't be wide enough, you'll probably need 3 or 4 strips with a small overlap. Paint the hull with resin first (thinly), lay each strip down and stipple some resin into it sparingly until it turns clear. Then if using D-rings you could paint a little epoxy onto the anchor straps, place them on the still wet resin and lay some more tape over the straps and wet it out in the same way as before, then you can be quite sure that the D-rings are securely embedded in the laminate (although they don't need to be bombproof for a strum box...). Remember use the minimum amount of resin necessary toi make the glass turn clear.

Assuming the boat is made with epoxy resin, make sure you sand the area you plan to laminate to key the surface - you don't need to go through to the fibres but do need to remove any waxy surface layer on the resin.

Jim

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geyrfugl
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Post by geyrfugl » Tue Jan 16, 2007 10:46 pm

Assuming the boat is made with epoxy resin,
If it's made with epoxy, be aware that polyester resin won't bond well to it. If it's made of polyester (most sea kayaks are, except the expensive lightweight ones), be equally aware that epoxy will bond fine to cured polyester, but then polyester will again not bond to cured epoxy, so epoxy may not be the best material to use to repair your seams. Also be aware that glass fibres are coated with an agent which links to the resin, so that glass intended for polyester resin won't work well with epoxy, and vice versa. If you are using epoxy, colloidal silica is a good filler material which gives improved abrasion resistance, and graphite powder is the classic black colourant for a shiny, low friction surface. OTOH, black toner from a photocopier or laser printer also works well for making things black... experiment a bit to see how much you need. In all cases, use proper resins formulated for marine use, not automotive resin or even araldite !

Lots of pitfalls for the unwary !

Having said that, I build boats using glass/epoxy and therefore cheerfully repair polyester boats with epoxy, as I won't ever be wanting to apply polyester, which is vastly more unpleasant to work with...

Andy

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mitchmix99
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Post by mitchmix99 » Mon May 14, 2007 7:17 pm

Finally got round to glassing in the patch where the old strum box lived......

Before

http://www.ibcsl.co.uk/kayak/boat2.jpg

After

http://www.ibcsl.co.uk/kayak/patch1.jpg

Did some practice work first as i'd never glassed anything before. Next job is to repair lost gelcoat from the ends of the boat. Ordering the bits up for that this week......

Cheers

mitchmix99

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Ceegee
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Post by Ceegee » Tue May 15, 2007 12:06 pm

Tidy Work !!!

You sure you have never done this before?

Steve

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mitchmix99
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Post by mitchmix99 » Tue May 22, 2007 8:38 pm

Looking for some advice on this again......

The ends of the boat are well worn and the black Gelcoat seam around each end of the boat is worn. Furthermore, a large chunk of gelcoat is missing from the front of the boat. My plan was do repair the gelcoat seam then repair the chunk of gelcoat that is missing. By repairing the seam first it will give me a good platform to repair the missing gelcoat.

My question is regarding the black gelcoat seam. Should I attempt to repair each end in 1 go or should I do 1 side first then do the other side? My concern would be the gelcoat running slighty with gravity, whereas if it's on it's side the gelcoat should stay more even. On another note, as i'm using black pigment the gelcoat colour my vary between mixes!

Any suggestions welcomed.

Image

cheers

mitchmix99

Chris Bolton
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Post by Chris Bolton » Tue May 22, 2007 9:28 pm

True gelcoat is designed for painting side a mould, and is thickened so that it doesn't run under gravity. For use in a mould, however, the exposed surface is designed to stay tacky - so use it on a seam, and the surface doesn't set.

Normal laminating resin is not thickened, and has a wax incorporated so that it hardens on the exposed surface as well. The trick is to mix enough laminating resin into the gelcoat so that it doesn't run, but hardens. Alternatively, get some thixotropic additive for the ordinary resin or some wax additive for the gelcoat! Places like Glassplies used to sell these.

If you've only got ordinary resin, then you'll need to do it in 2 stages.

Chris

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