Removing old outside seam^

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JohnML
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Removing old outside seam^

Post by JohnML » Sat Jan 28, 2012 1:24 pm

Hi,

I've got an old Anas Acuta that is pretty much cracked front to back along the seam both sides but for the cockpit and leaks like a leaky thing all over, in places the seam is totally gone and has damage to the deck/hull (like it had a run in with a grinder already) and for the rest but the cockput area its cracked all along with some fairly deep chips to the glass in places. Pics below including someones marigold resin fingerprints and drips of resin which are all over the place :/

Image

Image

Now I guess the best idea is to remove the seam, fix holes/hull/deck damage nearby, tape seam (worth it?) and recoat it like described in other posts here.

But before I start, how do I remove the existing seam? Sanding would take a lifetime, grinder + sanding the remainder would work quicker but could make a hell of a mess if it went wrong. Any easy way or just going to have to go for it?

John

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Re: Removing old outside seam

Post by surfkayaks.com » Sat Jan 28, 2012 2:31 pm

40-80 grit paper and elbow grease.

Mark T E
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Re: Removing old outside seam

Post by Mark T E » Sat Jan 28, 2012 3:45 pm

Hammer, very sharp wood chisel and lots of care. Most of it should chip off, then dremel with a sanding drum and again lots of care. Then use a vacuum cleaner to get rid of all the dust you'll be covered with.

JohnML
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Re: Removing old outside seam

Post by JohnML » Sat Jan 28, 2012 6:50 pm

Thanks, will have a crack at it with chisel, dremel and sandpaper seeing as there's not a magical no effort removal technique :)

First in a list of many things needing sorted on it!

John

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Mikebelluk
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Re: Removing old outside seam

Post by Mikebelluk » Sat Jan 28, 2012 7:55 pm

Mask either side with 2 layers of 2" masking tape about 3mm away from the edge of the seam, and use a random orbital sander with 60/80 grit disks, using the edge carefully at low speed.
Wear safety specs and a mask. You need a good rough surface for the new seam to bond to.
Time to get medieval on it.

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Re: Removing old outside seam

Post by rockhopper » Sun Jan 29, 2012 6:29 pm

Hi John,

I had exactly the same problem with the Anas that I bought. I found that a sharp wood chisel was the very thing as it was able to tap away the seam from the fibreglass hull. I started off lightly tapping the seam from above and the below and then just ran it along with my hands near the blade to remove any residual bits. Came off surprisingly easy. Then I cheated and got Valley to put on a new seam!!!!

Rog

JohnML
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Re: Removing old outside seam

Post by JohnML » Mon Feb 13, 2012 1:36 pm

Chisel to take away the bulk followed by sandpaper did the trick and happy enough with the result, did take a couple of chips of white coat out from under the black seam so if after doing a perfect job sandpaper might be best bet but the kayaks pretty battered anyway in this instance. I had the grinder on standby but thankfully wasn't required this time.

The more I look at the hull and clean it up the more problems I find though, repairs i can pick away, chine repairs that are nasty/lumpy, nice star crack hidden under a particularally dirty bit (I will bring a bucket, sponge and an inspection lamp next time I buy an old kayak!) All that along with the other stuff I knew about like cracked moulded rdfs, resin spills everywhere, bow that looks like an old boxers broken nose. Think it will be a while before this is on the water!

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Jim
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Re: Removing old outside seam

Post by Jim » Mon Feb 13, 2012 2:02 pm

Chine cracks can be hard to see and trace, even where an old repair gives you a clue. If you haven't yet, I recommend filling the boat with water (1 section at a time) and tracing any leaks you find, gouging gelcoat as necessary to identify the source, and marking them with a ring of permanent marker (which acetone will clean off later). Sometimes a crack extends through the laminate well beyond the broken gelcoat so check wheter water is coming out from under the gelcoat or through the laminate, if under the gelcoat you need to chip away and find the source. The keel of my sea king was so bad under the seat that I ended up patching it internally for about 3 feet in length by the width of the bottom.

However much you need to gouge out it will be repairable, but may add significant weight to the boat

Chris Bolton
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Re: Removing old outside seam

Post by Chris Bolton » Mon Feb 13, 2012 7:33 pm

Well done so far, sounds like good progress.
JohnML wrote:tape seam (worth it?)
Looking at the state of the original seam, there's definately been some movement at the joint. Ideally, it needs retaping on the inside, but that's a pig once the bulkheads are in, and probably not worth the effort given the condition of the boat overall. So I would definately recommend taping the outside. Laminate the tape on with ordinary resin to get good penetration, then put your thickened & coloured finishing coat over it.

Chris

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Re: Removing old outside seam

Post by JohnML » Sat Apr 28, 2012 2:29 pm

Seems the more you start on these things the more work you find, treating it as a learning platform now where mistakes don't really matter, not entirely sure I'm going to have it on the water this side of Christmas though.

Having patched up my overzelous chisel hits away which hadnt really appreciated (I may sand next time to save on that..) there were quite a lot of gaps where resin inbetween the hull and the deck had been, removed any loose bits and will fill tomorrow before fitting the strip, just picked up materials for this yesterday. It seems in one area the hull and deck were completely apart at some point as they dont line up 100% and is filled on the outside and patched on the inside, explains the cracking on the seam I guess.

Cleaned up the hull and sorted a few of the chips/cracks on the chines, but theres one really big bad area under the legs that I think is a bit beyond a gelcoat repair. It's mostly under one side but on the second picture you can see it spreading across the keel to the other side where its cracked a bit. These two areas nearly join each other.

Image

Image

I am guessing this is going to require something like glassing the inside to reinforce the area and then sanding a huge area of the outside and gelcoating? It's quite thin here gelcoat wise.

I will be sanding down whats left of the 3/4 keel strip layers (top layers sticky like glue for some reason and covered in crud) and replacing.

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Re: Removing old outside seam

Post by Graham T » Sun Apr 29, 2012 6:42 am

Jim will be able to explain the sticky gel coat better than I can but when used inside a mold it hardens when used outside of a mold it remains sticky unless either covered (I have used cling film in the past) or a wax ? additive is used.
It appears somebody has previously tried to do repairs and bodged them. The good news if you are enjoying the project is the Anas is a great kayak IMO.
I hope you manage to get her properly sorted out and have a great deal of fun paddling her

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Jim
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Re: Removing old outside seam

Post by Jim » Mon Apr 30, 2012 10:07 am

Graham explained pretty well, Gelcoat only cures properly in the absence of air so gelcoat filler has about 2% of liquid wax added, the wax floats to the surface and forms an airtight cover. An alternative is to use cling film or all weather tape to cover the repair but results are hit and miss for that. Best thing you can do is try to clean off the part cured gel with acetone or cellulose thinner (acetone is cheaper if you have a supply). If it is resin rather than gel then someone got the wrong amount of catalyst, in which case you need to peel the glass tape off and clean up the sticky resin with acetone.

I can't see the photos just now, they may be loading but are taking a long time?

On my Sea King I had so much keel cracking in way of the seat and just in front of it, that I sanded the inside of the boat and added quite a large patch or woven roving reinforcement (with epoxy) for the bulk of the structural repair. I haven't bothered with proper gel coat repairs since I worked in a boat yard - it's just cosmetics to me! For the Sea King I was lucky to find a little pot of tangerine pigment which fairly closely matches the boat colour, my 'gel' repairs are in fact epoxy thickened with silica and coloured with tangerine pigment. It's not an exact match but not glaringly different. I used the pigment to colour epoxy resin before adding my keel strip and chine strips so they don't stand out too much - I prefer a practical solution to perfection!

I may have to break my rule though and ask Mike for some gelcoat for my Taran, in my ongoing roofrack positioning nightmare I have lost a little blue and might as well try and match it properly. I have also lost a little clear but I will fix that with resin.

JohnML
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Re: Removing old outside seam

Post by JohnML » Mon Apr 30, 2012 12:39 pm

Hi Jim, pictures of the bad bit infront of the seat were broken but fixed them now. I'm guessing it is going to have to be an interior reinforcement, just a bit unsure about the outside fix.

Should have said the keel strip sticky stuff was there when i bought it and not part of my fixing. Although I've sanded most of the bit in the first picture you can see a dark fluffy bit to the top right, not sure what was used here but it sands/rubs off with a bit of effort.

Okay with the gelcoat and wax, have been using it on the various star cracks around the boat, my over zelous chiseling and to rebuild the ends a bit to let new tape sit better. Only issue I've been having is occasional air bubbles/small holes, guess somethings up with my mixing at too small a quantity, would be nice to get it perfected. Valley were kind enough to send a pot of matching deck gelcoat to fix some big bits there.

I'm beginning to lose patience with making it "pretty" though, it takes far to long and the fixed bits are making the rest of the boat look worse ;)
Last edited by JohnML on Mon Apr 30, 2012 12:53 pm, edited 1 time in total.

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Re: Removing old outside seam^

Post by Aled » Mon Apr 30, 2012 12:46 pm


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Jim
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Re: Removing old outside seam

Post by Jim » Mon Apr 30, 2012 5:12 pm

JohnML wrote:Should have said the keel strip sticky stuff was there when I bought it and not part of my fixing. Although I've sanded most of the bit in the first picture you can see a dark fluffy bit to the top right, not sure what was used here but it sands/rubs off with a bit of effort.
Hi John, I realised that, but essentially if the stuff hasn't ever cured, it should still come off with the right solvent - elbow grease and sandpaper might be quicker though.

I am really surprised to see the star cracking go through the keel strip tothe other side, but from the photo it is impossible to tell if it is just star cracking or a deeper problem. Does the hull feel quite flexible there? I expect it will after all these years so reinforcing it from the inside is a good idea.

I see one area where a chunk of gel is missing and the rest is just fine cracks, I would carefully (and wearing goggles) explore wit hthe point of a stanley knife from the chunk and see if the gel is generally loose and whether the laminate underneath looks OK or damaged. If it seems reasonably solid just fold some wet and dry paper to get a V profile and sand along all those cracks to widen them out to V's , then sparingly fill the V's. If it is bad all over that area, have a look at the recent thread about re-coating a hull for some ideas - a pigmented flow coat will probably be more appropriate.

Jim

JohnML
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Re: Removing old outside seam^

Post by JohnML » Mon Apr 30, 2012 9:22 pm

Hi Jim,

Thanks for giving advice. There is a lot of flex compared to my other kayak thats got next to none. Pushing hard with a thumb causes the other side of the bottom to flex in a little too and noticed a small crack opening and closing on the far side of the keel strip while doing this, not one of the spidercracks but a new one, yay.

Couldn't pick much of the coat off as it's pretty solid and doesn't want to come off but under the chipped bit looked fine, very thin layer in comparison to the other areas I've been sorting though.

Guess it is going to be a case of glassing most of the cockpit floor from under the seat to the bulkhead, fixing the cracks up then sticking a keel strip on. This was described as "very good condition" in the sale advert ;)

And thanks for the bubble tip Aled.

Cheers,
John

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Re: Removing old outside seam^

Post by JohnML » Mon Aug 13, 2012 1:47 pm

Getting there slowly, the boat has been renamed Starcrack in honour of the number of them it has, many repaired but I'm kind of sick of them, theres certainally a point where its just not worth it and the boat was well past that it seems!

The seam removal went okay, lot of patching due to my harsh chiseling followed by fixing up cracks and holes and filling the gaping holes between deck and hull with epoxy resin + silica. The bow and stern fixed up well considering the state of the rest of the boat.

Bow, before and mid job.
Image
Image

Stern, before and mid job.
Image
Image

Unfortunatally I messed up putting the final coat on the new seam. I think I needed to add a lot more filler to the gelcoat as it was too runny and didnt get a clear line along the boat as well as being a bit too shiny, also should have seived the filler first too as there are some lumpy bits which are noticable due to the shiny finish. Any other hints before I do the other side to get a cleaner line beyond making the mix thicker or is this the main problem?

Image

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MikeB
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Re: Removing old outside seam^

Post by MikeB » Mon Aug 13, 2012 2:09 pm

Mask it with tape - remove said tape immediately the seam has been done though, before it goes off. I don't recall having a problem with lumps, and I certainly didn't sieve the filler. I do recall adding it slowing and doing lots of stirring. Mike.

JohnML
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Re: Removing old outside seam^

Post by JohnML » Mon Aug 13, 2012 2:22 pm

Thanks mike, I left the tape a while which allowed some bits to soak under although most of the mess was down to movement after the tape was removed, remembered after I posted that I made a test patch on a bit of wood with a lot more filler after I'd finished and it looks perfect. So more filler, better stiring in and quicker tape removal..

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Re: Removing old outside seam^

Post by surfkayaks.com » Mon Aug 13, 2012 2:30 pm

The gel shouldn't need any filler in it, are you using a glass tape underneath?, also, masking tape is not ideal for a clean edge as gel will 'bleed" under it. , much better to use a "packing tape" coloured so that you can see edge.

JohnML
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Re: Removing old outside seam^

Post by JohnML » Mon Aug 13, 2012 2:42 pm

Used kevlar tape as it was the only tape I could find 15mm wide with epoxy and same for the topcoat with pigment so a good bit more runny. As said the test patch I did with a lot more filler looks spot on, should have done one first!

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Re: Removing old outside seam^

Post by nickcrowhurst » Mon Aug 13, 2012 4:16 pm

My old Anas Acuta had opened up between the deck and hull when I bought it, and there had never been a covering strip. I've done several of these jobs using 1 inch glass tape and clear polyester resin for the first coat, and Topcoat (polyester gelcoat +wax additive) + black pigment for the final coat. I use 3M blue masking tape, removed ASAP. The results have always been great. I've done much epoxy work, but I wouldn't use it for this job. Here's the boat:
Image

JohnML
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Re: Removing old outside seam^

Post by JohnML » Mon Aug 13, 2012 6:32 pm

Yeah, I'd just about gotten used to working with polyester gelcoat so maybe shouldn't have been so keen to use something else I've not used much before for the sake of it just because I had it as it's spoiled the finish. The boat is still a proper state elsewhere so a messy seam on one side is quite low down the list of problems just a bit annoyed I rushed the final step when I'd taken a lot of time for the previous ones and didnt test properly before hand.

Nice boat :)

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Re: Removing old outside seam^

Post by SJD » Tue Aug 28, 2012 10:53 pm

Question for JohnML and anyone else with knowledge,

On your AA, before your repair work, was there any kind of fabric covering the outside seam or was it just gelcoat?

My 1980 Nordkapp is doing the same thing as your AA, the seam is coming off in chunks and in places I can chip it off with a fingernail. There does not appear to be any fabric tape on the outside seam. However, my Nordkapp has a very solid taped 2" seam and it looks like there are end pours.

So, I wonder what is the point of this gelcoated seam without any other fabric/resin reinforcement?

Would simple heavy duty vinyl marine tape do the same thing?

I will eventually do a proper taped outside seam but was wondering if some vinyl tape will suffice until winter.

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Re: Removing old outside seam^

Post by nickcrowhurst » Wed Aug 29, 2012 6:53 am

1. There was no outside tape on my 1977 Anas Acuta when I purchased it. Not even gelcoat. Nothing....de nada....de rien..There was a weak laminate of glass tape on "most" of the inside seam.

2.Gelcoated seam without cloth is brittle and weak, but looks good for a while until it cracks.

3. Marine tape would be waterproof, but it would not supply the strength of a laminated cloth impregnated with resin.

4. Tape would work well as a temporary fix. Gaffer tape, Gorilla tape, Flashband are ones I have used successfully.

Nick.

JohnML
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Re: Removing old outside seam^

Post by JohnML » Wed Aug 29, 2012 3:19 pm

As with Nick just gelcoat on the seam of the AA when I got it, no tape. It leaked a lot as there were holes all the way along the join through to the inside tape before I filled them in.

I've done a couple of tests now that have cleaner edges than my new kayak but dare say that'll not work out the same when I get around to doing it on the AA..

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