Sheathing the decks

stevemeakin

stevemeakin

Member
Joined
6 Jun 2007
Messages
41
Location
Maldon, Essex
Visit site
Ok, contemplating the worse job I can imagine....epoxy sheathing the decks. What is the process as I'm not very clear on how to go about this? I understand that everything needs to be taken off (which I'm dreading), but I want to understand how you epoxy do the job.

Thanks
 
Great Question. I do hope there are some illuminating replies as I am faced with a similar problem and there seems to be little available "how-to" information. In my case I am hoping to keep it isolated to a few repairs around the stanchion bases, chain plates and one corner of the coachroof. Some of these patches will require openning up, scarfing in some fresh ply and patching the epoxy on top. But what materials? I have heard references to some guide by West Epoxy but haven't found a copy. What glue do I use for my plywood patch? do I put cloth/mat/other stuff in the epoxy? How do I acheive the lovely loose gritty finish? What about the end grain at the deck edge - how is this sealed?

So many questions! Such little knowledge! Combined with a distinct lack of funds to pay someone more skilled to do the job for me!!

And then if I remeber advice from this forum correctly the next step is to shun Blakes/International et al and head down to B&Q for some masonary paint.

another StellaOwner
 
Not the perfect answer, but I'll tell you what I've done for the 3 or 4 boats I've done. I'm sure others will, as ever, have other useful and valid suggestions!

Generally it's best to sheath over a new ply deck. So either completely replace the deck, or pay a ply layer over the top. Make sure it is firmly fixed with no movement, and then make sure all the fastenings are below the surface. Fair all the joins and fill all the gaps/holes with something suitable, for this hard body filler will do the job just fine. sand smooth. Now sweep, hoover, sweep and hoover to get all the dust and grit from the working area and a nearby surface.

Cut all the pieces you are about to apply beforehand, roll them very carefully and set them to the side in a pattern so you know which is which and which way each one unrolls and fits. As you cut each piece, it's useful to mark the join lines onto the ply so that when it comes to laying each piece, you can wet the right area of deck. Don't do this if you are not painting the deck, but prefer to see the timber underneath!

At this stage it's useful to have more than one person. you can then designate a "clean man" and a "glue man"; fairly self explanatory. It's very easy to pull thread when laying the cloth and then get ripples in the surface.

Epoxy the ply and leave to dry, this will soak into the timber and mean it all bonds well. Make sure the timber and epoxy are reasonably warm to keep the epoxy fluid and help it to penetrate - especially at this time of year.

Once the first coat has gone relatively green, but preferably slightly tacky, spread on a second coat for the area of the first piece and carefully lay out the cloth. It will become sticky immediately, and you will only be able to make small amounts of movement easily. This is why you cut out first and roll carefully!

Consolidate through the cloth with a roller, working in one direction, or out from the middle, whichever suits, and make sure all the cloth is thoroughly wetted and there are no air bubbles. Try hard not to stretch the cloth as you work it, as these bits have a habit of pulling back into shape about 2 hours after you leave a perfect surface, and the next day you find ripples and air bubbles!

Keep laying piece by piece, making sure there's plenty of epoxy on the joins, overlapping by an inch or so, and make sure you finish by a ladder!

Overalls, loads of gloves, lots of space. just take it slowly.

Deck nearly ready for sheathing, note pencil lines marking where the joins will be:
IMG_0985-1.jpg


Sheathing done:
IMG_0991-1.jpg


Make sure you set out the logistics - brushes/pots/rollers/working time/mix size/pieces/ladders/etc before you start, and then it's fairly straitforward!

i'm sure I've missed plenty, so others will fill in extra details and tips, or correct any mistakes I've made! /forums/images/graemlins/wink.gif

Jess.
 
Something I could write for hours about, because I spent most of last Spring doing this. As I'm based at Freebody's in Hurley there was plenty of useful advice from the guys in the yard, but ultimately I haven't been happy with the job I did.

You've got to get everything off, and then ensure it is all cleaned up and no hollow spots. I used the biggest Makita belt sander I could buy, so heavy I had serious wrist sprain for some time after. I then layed thin marine ply (from Robbins) fixing down with grip fast nails in a bed of thickened epoxy, having first rolled two coats on.
My prime mistake was not to lay enough thickened epoxy, such that after it went off there were spots which had not "stuck down", there then came a period of several weeks drilling into the void between the pine deck and the ply, pouring in more epoxy, and banging down with more grip fast nails.
In contrast, I found the sheathing part quite easy, and again use of the Makita achieved a reasonable surface.
I tried using pigments in the epoxy (called "poxy" in the yard) but this too didn't work well enough, but two coats of International deck paint finished it off well.

I have a 30' boat, did all three decks (foredeck, saloon, wheelhouse), used the West "C" (ie largest) pack, and just had some left over. Bought the rollers, (didn't get on too well), mixing sticks (invaluble), tape & woven roving sheathing.

If I did it again I think with the benefit of experience I could make a good job of it, but the thought of taking it off and starting again......

IanC
 
Oh, I can imagine much worse jobs!

BSJ has said it all but here are a few more pics- on a much smaller scale.

Cabin top

As has been said many a time, you need to get it properly dry first.
 
So have I really no hope of repairing a small patch in situ? I am a little reluctant to redeck the whole boat simply because a small area (of ply) has degraded around my stanchion bases. I am not sure what the existing sheathing material is are there easy non destructive ways to identify this?
 
Look up cfs fiberglass suppliers in Southport on the net, they have an excellent range of products, more important is they have a good booklet that explains what products how and when to use in what situation, I didn't realise for instance that Polyester resin does not actually stick very well to ply for instance.
 
A very good description.

I would only add a couple of suggestions as follows.

When mixing up epoxy use a drill and mixing blade for speedy consistent results.

Running an electric fan heater BELOW decks with the hatches shut will give a nice controlled,moisture free deck temperature on the outside. especially at this time of year.

You -may- want to try wrapping each piece of cloth around a cardboard tube and then unroll it straight on to the tacky epoxy.

Sounds obvious but cover up overnight to avoid condensation.

And although you are faced with removing all the 'stuff' before you start,just consider how leaktight and really secure everything will be once you have done the job and rebedded all the stuff soundly.

Good luck !

Edit. Re scarphing pieces into the deck.You can.but if the ply is dodgy in too many places it may pay to replace whole pieces.
Seal the edges with 2 or 3 coats of epoxy before laying the cloth,wrap the cloth down over the edges and then trim it when dry enough,finish with a wood bead well bedded in bedding stuff.(Sika)
 
Whenever you start removing pices of deck you <u>always</u> find more that needs replacing than you thought - so be prepared for a much bigger job. I too prefer to do a whole deck rather than bits and I'm not wild about sticking ply over an old deck. A whole new ply deck gives a better, stronger and more watertight job with less areas for potential future problems. If you can, scarph the ply rather than but joint.
 
Agree,scarphed and glued adds useful torsional strength sympathetically to the hull.
I have seen people prepaint the underneath of a new ply deck,thus saving themselves this messy chore later.
 
Done my fore deck 2 seasons ago and doing the afterdeck as we speak. In my case there is teak going over the top of the ply but some hints still valid.
Work out how to keep the weather out while you do the job.
Cut back all the crap ply. make a card or thin ply template of the required patch. consider how to scarf the joint as you will never make a watertight but joint ( I used my router to remove one ply thickness on the old and new wood. Cut and route the patches in your workshop/kitchen, seal with thinned epoxy (25%meths) and a couple of epoxy coats. On the boat seal the scarfed old ply, screw down the new patch, seal the screw holes with dripped in epoxy, epoxy in a patch of construction veneer to fill the scarfed bits. more epoxy and you may be water tight.
perhaps just do one patch first; this is an 'uneconomic' way to progress but will help the learning curve!!
 
One of my friends who owns the Dunkirker "Minmosa" did a neat trick to his rear saloon roof. He routed out "V" joints in a sheet of ply, to make it appear like a T & G "V" jointed planks, epoxyed and painted the underside, and then laid and epoxyed/painted the top. Looked totally traditional but very strong and completely watertight.

IanC
 
one of the best threads ive seen!

For epoxy decks its the best and only way to do it.The fan heater belows a very good idea.

Of course epoxy!! Much better to canvas the deck! That way the wood below will stay fresh and all below will still enjoy authentic leaks.
 
Haha Trouville,

I admire your enthusiasm - yes lots of good input.

Only a slight disagreement ... even though I am a big supporter of epoxy technology there is never just one way of doing it!

:-)

I know you didn't mean it that way ... but it enables me to make an important philosophic point.

thanks and best wishes
MIK
 
"Tip! Tape a skirt about 1." all aroud the hull, stops any dribbles geting on the hull"

Why, oh why didn't I do that! Painted over the dribbles of epoxy to get back in the water, got to cleam them up in next few weeks.

IanC
 
You must log in or register to reply here.

Other threads that may be of interest

B
Halberg Rassey 31
2 3 4
Replies
71
Views
2K
ashtead
ashtead
ianc1200
Sureseal shaft seal.
2
Replies
20
Views
556
ianc1200
ianc1200

Share this page

Top