GRP or ply?

[Nick Lawson]

I intend to buy a Storm 17 ready built and would appreciate some guidance on the choice of GRP over ply.  Apart from the consideration of price, I understand the GRP boat has a different hull shape and also weighs more.  I assume the extra weight of GRP will make the boat more stable on the water but harder to handle off.  I have heard good reports of the durability of modern ply boats so don't know if GRP is the obvious choice on that count.

I may well end up having to launch and retrieve the boat on my own so the lower weight of wood may be a godsend.

Any views would be welcome.

[Julian Swindell]

I can't comment on the Storm range, but I have an epoxy ply Baycruiser and I love the material. The boat is very light, it is very easy to add or move fittings and it seems completely durable. I spend all winter tinkering with it in a way I simply couldn't do with GRP. I would choose it as a beter boat material even if the costs were the same.

[Andy Dingle]

Hi Nick
I have the epoxy ply Bayraider, (BR12), like Julian I am very pleased with it. She is very light and strong but still very stable. A very significant point when moving her around on her trailer ashore. Like you I find my crew suddenly finds she needs to visit the ladies when the boat needs to be shunted around! On the water, I find that I rarely need to fill the water ballast completely, (except in heavy weather), as we both like the speed she can achieve in a decent breeze.

Although the GRP option wasn't around when I ordered my BR I certainly think that the epoxy ply material is worth every extra penny it cost.

Dare I say too that apart from the ease of maintenance, I think the epoxy ply hull looks better. I have the strip plank decking in mahogany on my boat and she looks stunning!

Regards

Andy Dingle

BR12 'Psalter'

[Craic]

Nick,
my SeaRaider is Wood-Epoxy, my first BayRaider, No. 11, is GRE -Glass Reinforced Epoxy-. My other BR No. 39 is GRP -Glass Reinforced Polyester-.

I very much prefer the plastic boats for their durability and their lowest possible maintenance. The GRP BR hull is the toughest of the lot.
That boat is practically bullet-proof, and considering it is also the cheapest of the lot, I would go for that again any day.

The wood-epoxy hull is fairly lightweight, true, but that comes a price. First, it is a lot more expensive to buy, and secondly, the 6 mm wood hull punctures quite easily above the waterline (the glass hardened part is under the waterline). I had two punctures (splintered indentations) there from very minor encounters. And as most of the above waterline area is double-walled with airtanks under the gunnels, repair can only be done from the outside.

Then also, the wood epoxy is difficult to repaint, a lot of sanding required. My 2005 SeaRaider needed a new paint coat in the cockpit and on the deck. I just couldn't do it myself, with all the tiny details. I had to give it to a pro, and paid a bundle for it. The GRE and GRP hulls on the other side still look like as new, even though they have done a good bit of mileage on the road and on the water.

Wood or plastic, your own decision.

[Julian Swindell]

It all depends on you and what you like to do. I have just completely repainted my BayCruiser as she was quite knocked about last year. It isn't a big job, provided you have somewhere to do it (big proviso). I did the whole thing over last weekend.

The outside of the hull takes about half an hour to mask with tape and maybe 45 minutes to roller dark green. It has come up like a mirror, which has surprised me.

The topsides, cabin and cockpit take longer because of all the cleats, fixings, hatches etc. but still, I reckon it took me about 2 hours to mask and about the same to paint. I'm not a perfectionist, so a little paint on the edge of hinges and things doesn't bother me. 

What I like about a painted finish is that you can move fittings around with gay abandon as it is so easy to make good to old screw holes. A bit of marine filler, a quick sand, a couple of dabs of paint with a foam brush and it looks like new. I never found a way of really making good to the gel coat finish on my old GRP boats, to the extent I eventually painted one. (I didn't like the original colour anyway, and it had gone dull). I haven't had to deal with any puncture repairs (touch wood) but it would be easier on the BayCruiser than the Raider I think as the side decks are open, but repairs from one side are not all that difficult with epoxy and plywood patches. I have repaired bullet holes (don't ask) on a GRP dinghy from the outside and it is really quite easy.

[Craic]

... It isn't a big job ... . The outside of the hull takes about half an hour to mask with tape and maybe 45 minutes to roller dark green. It has come up like a mirror, which has surprised me. ...

What? No sanding of the old coat?
Last -and only- time I did that it came up like a mirror too. Only, parts of it came off again in flakes half through the season and then things looked -and were- really horrid.

Re damages in a plywood hull: If you have a splintered indentation in a plywood hull, and cannot get at it from inside, you sure can patch it over on the outside. But that is only superficial. The structure underneath remains broken and inside the inaccessible cavity the wood fibres remain to lie open and remain unprotected against the moisture inside the cavity. Plywood is no plastic, it deteriorates faster where you have moisture getting in.

[Tony]

Hi, Nick.
I have a Cardigan Bay Lugger in ‘poxy ply. 
I probably would have asked for GRP but she was the prototype so it wasn’t an option. With a production run of 3 so far (unless I’ve missed something) chances are there never WILL be a GRP version!
 Am I bovvered, though?  No!  The boat is a total delight to trail and sail being so light. I rather think the cabin is better insulated, too, but comparisons are subjective and difficult.
Downsides to EP?  Very few with this modern stuff.  True,  the sanding is a pain in the proverbial  -  and I have to call my splodgey   attempts at re-painting  “Workboat Chic”    but I feel more comfortable with wood than GRP.  Just lack of practice with latex gloves, really.

Just one point.  Where I sail the surrounding geography makes the bit of water just around the pontoon subject to really  fluky winds at times, gusting from different directions without warning. (They call it a Rotator.... or some such.)
I “tut tutted “  smugly when a chap in a nice new (and solid-looking) plastic gaffer got caught out recently.  What was a measured approach suddenly turned into panic stations as he careered into the pontoon at a rate of knots, flexing the port bow with a nasty splintering noise.  Sounded expensive.   I wasn’t so smug when I did the same thing myself a week or so later! If anything I was moving faster but I just bounced off with a solid sounding “Thunk”!  Bit of varnish off the rubbing strake otherwise nothing. Nada.  Ziich!  (No wonder Matt can afford to give a 6 year hull warrantee.) I did something similar a month later....this time I went up the beach like a D-day Landing Craft.  No rocks, thank Goodness, so I didn’t even lose any paint. Stepped nonchalantly over the bow and fetched the trailer as if I do it all the time!
(I might be a slow learner but now I drop the sails and row in from 200 yards out.....  discretion being the better part of seamanship!)

[Tony]

Hi, Nick,yet again...

Forgot to say (too busy spinning a yarn, as usual)  Claus is dead right about the insidious effects of water ingress at the site of damage - or old screw holes. 
Wood rots.
Its supposed to rot. The bacteria and fungi responsible have had millions of years to perfect the cellulase enzymes that do the job. Before they recycle your wooden boat, develop the habit of slathering every ding with epoxy (after a suitable drying out period) to keep 'em at bay for as long as possible. I think, with care though, I should be able to pass my Lugger on to the Grandchildren. (Unless they carry out their threat to pack me off to a Care Home...in which case all bets are off!)

Ah! but just wait till the Diesel Bug evolves a new set of enzymes. Crisp packets, polycarbonate bottles ( and plastic BayRaiders) will become Biodegradable  overnight!

[Craic]

Nick,
you will have got the message now that plywood boats are not as maintenance free as you may wish, and are ready to rot if you neglect that maintenance.

Your other concern was that you may have difficulty handling the somewhat heavier plastic version of the S17. Absolutely no reason to be concerned about that, as most of us here can handle the really much bigger plastic BR 20 without assistance. 
Hope this helps.

[Anthony Huggett]

I understand from Matt that Swallow Boats build all their wooden boats by pre-coating the plywood with epoxy (I'm still doing this step on my home built BR17).
 
Regarding Claus' point on repairing a punctured wooden hull, leaving exposed fibres is certainly undesirable. How about the following method? Suggestions for improvements welcome!
 
1) First make the hole bigger, back to firm wood and get the edges smooth with sandpaper.  It must be made oval rather than round, or rectangular rather than square.

2) Make an inside patch, larger than the hole all the way around by say 1 inch. If your hole is now 1 inch by 3, the inside patch will be
3 inches by 5. Make a couple of finger holes in the middle of the patch piece.

3) Seal the inside patch with epoxy, including the finger holes. Do the same around the edges of the hole. Allow to cure fully. Sand to remove amine blush. Also poke your finger into the hole in the boat, and sand around the inside of the hole to provide a key for the glue. You want to remove any bilge/locker paint, into the epoxy or bare wood.

4) This is the hard part. Put epoxy all around the inside of the hole. Now you have to post the inside patch into the boat, without losing it into the tank, and draw it back towards the hull. To do this, put a piece of thin rope through one finger hole, and back though the other. Keeping hold of both ends of the rope, post the inside patch into the boat, draw it back so it is flush with the inside of the hull. Fiddle with it so it is nicely over (or should that be under) the hole, and tie rope tightly around a batten on the outside of the boat so that it pulls the patch tight. Clean up any excess glue and allow to cure.

5) Remove the thin rope and batten. You now have a recess into which you can simply epoxy a second piece of (pre-sealed) plywood from the outside, and finish off.

 
Caveat - this is just a suggestion, I haven't actually tried it and I hope I never have to.



Anthony

[Julian Swindell]

Hi Anthony
This is how I have repaired holes in the buoyancy tanks of a GRP dinghy. It should work perfectly fine on an epoxy ply skin. The trick is to have the nerve to make the hole bigger, which is always hard to make yourself do. If the hole is very large, there is a risk of getting a flat patch, but fairing the surface should sort that out. Rather than finger holes and rope, I have used very small holes and copper wire to hold the patch whilst the glue sets. Then just snip off the wire. I outlined the work I did a couple of years ago on my website at:
http://www.jegsweb.co.uk/boats/bluepeter/home.htm

[Craic]

Anthony,
thanks for your suggestion. A very thorough approach. However, even a well repaired hull remains a repaired hull. And with regards to the resale value of the boat I would rather give such work to a professional boatbuilder (and I did actually).
Resale value should be another keyword in the GRP-or-ply discussion. Would I consider buying a 30 year old plywood boat? I would not. Would I buy a 30 year old GRP boat? I did, and didn't regret that.
As I know I am not alone with my view on aged plywood boats, I suppose there is a general rule that the resale value of plywood boats declines faster than that of GRP boats.

[Anthony Huggett]

I think there is an important difference between wood repair and GRP. Where you have no access to the inside of the hull, the wood repair I proposed, if done properly (good adhesion all around) should be as strong or stronger than the original, at the expense of extra weight. With a blind hole in GRP you are at a disadvantage because you cannot laminate over the inside to restore the strength, and it will be much harder to restore the outside to the same finish as the original gelcoat.

GRP is not perfect - you can get crazing of the gelcoat, especially in high stress areas, which can be difficult and or expensive to put right. I had an early GRP yacht (Hurley 22) where the gelcoat on the foredeck was flaking off in cornflake-sized lumps!

I think there's much to be said for both materials, but neither is perfect. Since I'm a home builder I'm obviously happy with wood, but if I were not I would probably go GRP, for cost and maintenamce.

So I think the advantages are:
Wood (Epoxy ply)
Lighter.
Easier repair.
More traditional/nicer (whatever that means).

GRP
Less maintenance.
Cheaper.



A final thought (and the answer is by no means clear to me, so please comment). Considering the lifecycle of materials from forest or oil rig to when your boat finally goes to Davy Jones' locker, which is the more environmentally friendly material?

Anthony

[Nick Lawson]

Thank you all for your comments - I really appreciate being able to benefit from so much experience. Incidentally, I remember my father repairing a split in the hull under the side tank of our Mirror Dinghy about 30 years ago by cutting out a rectangular piece of the hull and patching it from behind with an over-sized piece.  He threaded some string through a small hole in the patch to hold it in place while the epoxy cured and then snipped it off.   

If anyone is interested, I think I'll got for the GRP.  While I do think there is something special about wooden boats, I can see that lower maintenance will suit me better and I probably won't be messing around with the rig very much.

Kind regards

Nick

[Richard Cooper]

Hi Nick

I have a GRP Storm17, one of the very first ones Matt produced, built in 2006 and sailed for 5 seasons now.I can echo Claus' comments about robustness. We sail mostly in Poole Harbour in tidal conditions, and its not totally uncommon to have accidental comings together with channel marker poles and the like. We have picked up a fair few scratches and bumps, but have come out unscathed really.

If you are worried about handling on dry land on the trailer so long as you have a flat road/drive don't be.

As regards launching, get the small Bramber swinging cradle trailer, because as with any boat the main issues are going to be keeping the boat straight especially if you launch from a slipway which is side on to the tide. Two of us can hand launch and recover and pull the boat up the slipway in Poole without the car no problem, we could never do that with our Drascombe Lugger, if you have a slipway where you can drive to the water it will be a doddle.
There is no doubt that in light air the wood epoxy Storm17 will go faster, but when the breeze gets up the GRP is quite stable.

Go for it, you won't regret it!

Richard Cooper