retrofitting new hatch types to my old Nordcapp.

[Teaman]

Hi.
Tis the season to start getting my boat ready for summer. I noticed that last year I had water ingress on my nordcapp.
It is a rather old one but I like it. The only things I don't like is the access hatches.
two at the rear, one at the front.
The alleged day hatch is accessible from inside the cockpit and it leaks, This I know and want to remove this hatch and fit one on the outside.
The front and rear main hatches are the old screw type and sometimes I can't undo the blooming things.
Whilst I'm not getting water flooding in I think I would prefer new hatches.
Could anyone recommend what types I should be looking for?




oh the water in the first pic is I noticed the ingress so I filled it fully and checked the outside. I couldn't find any so I had to assume that its the fit of the seal on the hatch.

Thanks for all the advice in advance

Stu

[MikeB]

If they are the old-style Henderson (screw on) hatches, then I believe Valley hatch covers are a straight swop, and will fit the existing rims.

[gnarlydog]

I much prefer the KajaSport ones, like on the SKUK kayaks.
They are easy to put on, last forever (don't perish like VCP) and seal really well.
Make sure you ask for the full rubber ones, not the dual density

[Ceegee]

I will go with Damio on this.

Have built/renovated several boats, and used Kajaksport hatches and rims every time. Karitek stock them. Around £20 each (hatch and rim).

It is worth replacing both, and GLUE (don't bolt) the rims. The reasons for this are 1) the screw loading points means water can seep under (uneven pressure around rim) and 2) the screw-heads inside can snag dry bags etc.

Use a high quality methacrylate glue (ITW Devweld etc). Not cheap but it sticks and seals!!!!

(and yes, tie them on - they sink - there is a lug molded on the underside for this)

[Simongelder]

It is worth replacing both, and GLUE (don't bolt) the rims. The reasons for this are 1) the screw loading points means water can seep under (uneven pressure around rim) and 2) the screw-heads inside can snag dry bags etc.

Use a high quality methacrylate glue (ITW Devweld etc). Not cheap but it sticks and seals!!!!

The Kajaksport website and Nigel Denis etc advise using Sikaflex to bond rims to boats. As soon as I have finished the deck recesses for my previously hatchless Nordkapp I will be gluing the rims on. I have bought Sikaflex for this purpose but have seen elsewhere (eg American cedar strip self build sites) that thickened epoxy can also be used as well as the methacrylate glue advised here. I understand that if in the future a rim gets cracked, it will be easier to remove and replace if Sikaflex has been used. I am still dithering about whether I would be more confident of the strength of this crucial fixing if I use epoxy. Officially Sikaflex should be used as an adhesive following surface preparation using their primer which is prohibitively expensive. What do others advise?

[gnarlydog]

A week ago I finished resetting 3 hatches on a Point65N that were installed with polyurethane (like Sikaflex).
Admittedly the factory job was appalling and the hatches leaked, badly.
The previous owner of the kayak tried to fix the problem with silicon, with very little success.
It took me hours trying to get rid of the pesky silicon that in my opinion it's a material that has absolutely no place in kayaks (for the above mentioned reasons: a real bitch to remove!).
I seated the rims with thickened epoxy (microfiber) and a bit of dye tinting to match the color of the deck as I didn't fancy seeing the white glue squeeze out to the edge. The epoxy I used is UV stabilized to avoid future chalking (if not UV resistant it goes white and powdery after a while, in the Australian sun).
I have re-seated other rims before with thickened epoxy with great success.
In the event the rim would get damaged (as mentioned) I think salvaging it would be out of question therefore I would just use a grinder to take off the plastic rim and then a high speed drill (Dremel) with cut/sanding wheel to finish the job neatly. The new rim would cover the area that would get roughened by removal of the epoxy glue.

[Simongelder]

Many thanks! My gut has been telling me to use epoxy despite having bought the Sikaflex for this purpose (particularly as I won't be using their primer)! I will be putting another layer of laminate on the surface of the new recesses so if I get my act together and glue the rims straight after, this will give an even better chemical bond to the deck surface. It will also mean that I can use pigment in the 'glue' to match the deck.

[Teaman]

Added the Karitek website to my Faves. Thanks for that.
I'll have to buy some new sikaflex as I forgot to freeze it after use so its gone like rock. That stuff is a bugger.
It holds my sheep mascot on my creek boat so proven to keep things stuck on :D
Impressed with the price of the hatches and covers. I think it will be a buy next week. I just need to wait for the snow to melt so I can get to my boat and unwrap it.

[Teaman]

I've just phoned Karitek and I have to say what a helpful bunch of people.

so ill be ordering the hatches now :D

[Mikebelluk]

I recommend Sikaflex over epoxy, as it has a small amount of flexibility when cured, and epoxy is brittle. Use some rough sandpaper to really roughen up the glueing surface of the rims and the boat to get a better bond. I failed to do this once and the rim came off as I was taking the hatch off..embarrassing.

[gnarlydog]

and epoxy is brittle

epoxy is brittle indeed, if used on it's own.
Epoxy and epoxy-glue are two different things that often people confuse one for the other.
Epoxy glue uses the resin as base AND includes additives/fillers.
Just like epoxy on it's own would not work to create a hull but when bonded with glass (or other fabrics) becomes highly suitable for laminate construction.
I did that mistake initially: use epoxy on it's own and indeed had disappointing results.
So, try to mix-in some microfibers (you can make that yourself by chopping extremely fine light glass cloth, however the stuff I buy is always better/easier to use) to create a paste the consistency of thick mustard (unlike thin honey that epoxy alone gives you). Once cured try to break it and see if you can call that still brittle.

If epoxy was really brittle, how could it be used in the lamination of composite kayaks?

[MikeB]

I recommend Sikaflex over epoxy, as it has a small amount of flexibility when cured, and epoxy is brittle. Use some rough sandpaper to really roughen up the glueing surface of the rims and the boat to get a better bond. I failed to do this once and the rim came off as I was taking the hatch off..embarrassing.

As above, and clean off the surface with acetone to remove any grease / muck / wax.

[Ceegee]

All I can say is I talked to Mike Webb at Rockpool and they use (and he recommended) IWT Devweld for hatches, deck-line recesses etc. It comes in a 50ml double syringe a for around £15 (enough for 2-3 hatch rims) and (ideally) needs a dispensing gun which is a bit more. That said, Mike said they have never had a hatch rim come loose, and I believe him. I have put in 6 hatch rims like this so far (Kajaksport ABS onto gelcoat - it does not bond to certain types of polypropylene) and they are rock solid.

Devcon-Devweld Data Sheet

[laca]

Hi,
I've a similar Nordkapp and I replaced the hatches about 6 years ago with the new 20cm Valley ones (and built a kajaksport dayhatch).
I've used Sikaflex (the previous version of now called 291) with cleaner and primer. It's still bombproof. My recommendation to use Valley hatch with Sikaflex because this hatch cover sits higher on the rim (left more space between the rim top base and the cover bottom) and you can not only glue the rim but also you can fill up the recess (it drains all water around the hatch).

[gnarlydog]

Rockpool and they use (and he recommended) IWT Devweld for hatches

a quick web search shows that it's an epoxy glue, of course conveniently packaged and ready to use.
A similar glue can be made with ordinary epoxy and some microfiber additives, with a bit more messing around; think of it as making the icing for a cake :-)
Sikaflex works ( I have used it for hatches) but does not have nowhere near the strength of epoxy glue.
Your call: convenience or piece of mind...

[Ceegee]

Well the actual adhesive specified was ITW Plexus 310, which seems difficult to get in the UK, and the DevWeld seems to have supplanted it here. Despite it being advertised as an "epoxy" the datasheet confirms it is a meth-acrylate. And from the smell and characteristics, it is definitely not an epoxy.

A note on MMA's (adhesives.org)

Methyl methacrylate (MMA) adhesives have a different cure mechanism than other two component reactive adhesives. The ratio of resin to hardener can vary from 100:3 to 1:1. MMA adhesives are typically less sensitive to variations in mix ratio and variations in the degree of mixing. The cure profile of MMA adhesives can be adjusted more readily than other types of two component adhesives. This allows formulation of adhesives that have a slower reaction rate immediately after mixing to allow more time for adhesive application and assembly of parts (longer worklife). After a short period of time (induction period), the rate of reaction increases to provide more rapid strength build-up. This reduces the time components need to be fixtured before bonded assemblies can be processed further.

That said, you takes your choice.

[flat earth sails]

mMA glues are the best to youse but be awear of thear volitile nature , ther realy bad for your health if you dont youse the apropriat precortions , worce than epoxy

[gnarlydog]

ah, so MMA is like epoxy, but better. It seems to have a longer working life (good I guess) and it seems to need less clamping (or hold in place till cured) after application while increasing in strength.
I like that.
Can it be tinted so it matches the gel color of the deck to make it more attractive and less "chewing-gum look" between hatch rim and deck?