Swallow Yachts Association
Swallow Yachts Forum => Home Builders' Area => Topic started by: Michael Rogers on 27 Nov 2010, 09:41
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Hallo Everyone
I will shortly be starting to build a Trouper 12 (just to be different!). Actually this will be my second Swallowboats build - the first a Storm Petrel in 2003- so I have some idea of what's involved, and to say I'm looking forward to it is putting it mildly. I wondered whether I could tap collective experience on two practicalities -
1) Does anyone have tips on the best way to fill the holes of holding screws with epoxy once said screws have been removed? (Obviously width and depth of hole come into this.) Really runny mix and try to coax air bubbles out? Much thicker mix, insert a 'worm' and tamp down? Any other ideas?
2) Has anyone used peel ply? Does it help? Any downsides, apart from extra cost? Opinion on the web generally seems quite sharply divided.
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Hi Michael
I've just finished the hull of my Storm 17 which has been really great fun. Painting may be a different story however!
I filled all of the holes left by the holding screws with epoxy thickened with micro-balloons which sand really easily.
I used peel-ply on all of the taped seams and the undersurface of the hull and would definitely recommend it. It does add a little to the cost but makes final sanding much easier - so what you spend on extra epoxy/peel-ply you might save on sanding discs.
I also epoxied and finish sanded each panel before assembling the hull. Again this makes final finishing much easier, especially inside the hull - it's much easier to sand flat panels on a bench than curved ones inside the finished hull.
Hope this helps and have fun!
Simon
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Thanks, Simon! Really helpful.
Matters arising, so to speak - epoxying the panels before assembly (on both sides, I presume?), did you have any problems either bending the panels (they must have been quite a bit stiffer than they would have been uncoated), or with the epoxy coating tending to crack when you bent them to shape? Presumably the glass cloth takes care of this?
I realise the answer to these queries may be self-explanatory to anyone who has done epoxy-coating, which I haven't to date. When I built my Storm Petrel in 2004 it was specifically NOT recommended to epoxy coat: the hull is 4mm ply, and I think it was thought that inevitable 'micro-flexing' at least of the bottom panels might cause cracking of the epoxy (I got the impression that this advice may have come from West System). Clearly experience since has been that this doesn't happen, and epoxy coating seems now to be standard practice.
Best of luck with the painting. My experience was that it took much much longer than I had thought it would to get a decent finish, but it's worth all the time it takes in the end. What are you going to use inside the hull? I used Sadolin Superdec Satin (white), a water-based micro-porous paint. This is absolutely superb and amazingly tough on bare ply, but it noticeably sticks somewhat less well to epoxy where the seams are taped, so might not be the finish of choice on epoxy-coated surfaces.
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Hi Michael
I too was worried that having epoxy coated the panels inside and out they would become too stiff to bend to the necessary curves as the hull takes shape - not so!!!
In fact it seemed to make no difference at all as I guess the epoxy is very flexible.
This method also has the added advantage of making the panels much more resistant to the inevitable dings during the building process.
I'm sure I don't need to say this but I found it really important to let the epoxy cure completely before sanding, to wash the epoxied panels with water and to change sanding discs frequently.
A couple of other tips which you might find useful!
Initially I found filleting to be a really messy, difficult and frustrating job.
This was made MUCH easier when I tried using a large 50ml disposable medical syringe with a catheter tip (approx 5mm diam hole) to load up with thickened epoxy and just laying a nice fillet down where required. It delivers just the right amount of epoxy for a good fillet and gets into tight spots easily. Having laid down the epoxy, I then formed it with disposable wooden tonque depressors (remember at the doctor's - say aaaaaagh!!) These are very cheap and form a fillet with a perfect radius and minimal mess/waste.
I used about 20 syringes and 50 tongue depressors.
They're available widely on the net but if interested you could try: www.medisave.co.uk - or speak VERY nicely to your local GP!
The items are: B&D 50ml catheter tip syringes and Premier wooden tongue depressors
I'm planning to undercoat my hull in Pre-kote and then Toplac (with matting agent inside). I have been thinking about spraying it. Does anyone have experience of spraying I wonder?
Anyway this will all have to wait for springtime as she's now tucked up under wraps for the winter.
Cheers
Simon
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Thanks again, Simon. I hope other people are benefitting from our rather public conversation - I certainly am!
Your filleting tip is a good one. In my previous (pre-retirement) life, which is a good few years back, as a medic in the NHS I had very useful access to tongue depressors. Not only is this now denied me, I suspect that 'stock control' these days is a good deal tighter than it used to be! For recent epoxy stirring I have been using wooden lolly sticks, but even these are being usurped in the shops by bits of plastic, and they don't have the width of blade which is so useful in a tongue depressor. I can't remember now how I went about filleting first time round, and haven't filleted in earnest since then, but I will certainly try the 50 ml syringe approach.
I hate this cold weather! - but anyway my kit will not be ready until the end of Jan, so I have some heel-kicking ahead of me (as if there aren't several dozen house/garden/outbuilding jobs queuing up for my time). I have, however, been doing some R&D work into rope along-the-gunwale fendering which, if properly done, looks great and is very functional. If this would be of wider interest, I could try to describe what I plan to do -??
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Michael and Simon,
Great conversation! I've just taken delivery of a kit and I greatly appreciate the tips on filleting and filling.
Has anyone tried using a smaller syringe to fill the screw holes?
Anthony
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as a medic in the NHS I had very useful access to tongue depressors. Not only is this now denied me, I suspect that 'stock control' these days is a good deal tighter than it used to be!
Hi, Michael.
Sorry to intrude on a subject I know nothing about (but ignorance never stopped me having an opinion)
Have you tried http://www.expresschemist.co.uk/product_4087_wooden-tongue-depressors-100x.html ?
Do-able, even on my pension.
Cheers!
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I've tried syringes for filling holes. It only works if the hole is larger than the nib on the top of the syringe. (I have not tried using needles in the syringe)
Ebay is good for syringes, tongue depressors, and chopsticks.
Get disposable chop sticks, they come as a pair that you snap apart.
Without snapping them apart, break one of them in half. Put the long end into a drill chuck and you have a perfect epoxy mixer.
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I can see the funny side of helpful forum members telling a retired medic where he can get tongue depressors from (thanks, guys, the links are helpful), but I probably didn't make myself clear. In my day the supply cupboard doors opened easily and in such a way that said TDs fell out into my bag rather faster than I used them to inspect tonsils, so that there was scope for lateral thinking such as epoxy mixing and filleting. These days I am sure some sort of dragon keeps the key to the cupboard. Anyway, to quote W S Gilbert, " I am now a respectable chap, and shine with a virtue resplendent" (Trial by Jury), and wouldn't dream of such behaviour in this age of cost-cutting, even if I was still in harness: hem-HEM. I was, of course referring to the intra-NHS situation, and was aware that most medical kit (operating theatres, glass eyes, the lot) is available on the internet if you know where to look.
It may have been noticed that I sometimes ask a question and then sort out the answer myself. So it is, probably, with hole filling. The point is to make sure the hole is watertight and then achieve a flat surface for finishing. I'm sure it doesn't matter, structurally or otherwise, if the hole (most holes, anyway) isn't full of epoxy right to the bottom. The problem with a runny mix (which you would need if you tried to use a small syringe, Anthony) is that an air bubble is usually trapped, it looks OK, and then when it cures you've got a dimple because the air worked to the top and the remaining epoxy sagged into the hole. I'm sure Simon's approach is right, using the micro-ballon filler and a reasonably stiff mix, and leaving a blob over the hole to sand smooth.
Incidentally, something else which has changed since I was actually building (in 2004) is the range of fillers now available. At that time, 'easy sanding' in the context of epoxy was definitely an oxymoron, and I'm looking forward to a somewhat easier life in that respect this time round.
I have to say that, since Simon's initial reply to my first post, I continue to be mildly gob-smacked by his idea of sheathing panels before assembling the hull. It seems to make every kind of sense - doesn't it? Anyone else got any comments? Am I being completely naive in finding it so brilliant? Does everyone do it? Anyway, I shall certainly do the same when the time comes, unless other builders have cautionary tales advising against.
Anthony, you haven't told us which boat you are building. It's a great experience, enjoy!
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I can see the funny side of helpful forum members telling a retired medic where he can get tongue depressors from (thanks, guys, the links are helpful), but I probably didn't make myself clear. In my day the supply cupboard doors opened easily and in such a way that said TDs fell out into my bag rather faster than I used them to inspect tonsils, so that there was scope for lateral thinking such as epoxy mixing and filleting. These days I am sure some sort of dragon keeps the key to the cupboard. Anyway, to quote W S Gilbert, " I am now a respectable chap, and shine with a virtue resplendent" (Trial by Jury), and wouldn't dream of such behaviour in this age of cost-cutting, even if I was still in harness:
Yes, but other might read the thread, and might want to know where to get things.
Some might not dream of such behaviour regardless....
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most medical kit (operating theatres, glass eyes, the lot) is available on the internet if you know where to look.
Not too keen on light opera, especially not in an operating theatre, but I could use a few glass eyes for my next Greek trip. (Blue, for warding off the Evil Eye and improving the fishing, etc.) E-Bay, you reckon?
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Hi Michael
It's great to hear of other people out there who are enjoying the delights (and frustrations!) of building beautiful wooden boats.
When I built my hull I found the forum really helpful and a constant source of inspiration and support - it was always good to know that there were others who were facing the same challenges.
So if it helps - another tip from a recent builder.....!
My main friend during the build was a good quality, low angle block plane, kept very sharp:
After you have made your scarf joints between the hull panels you will be left with a bead of hard epoxy which sits proud of the panels which you have joined.
Initially I sanded these with my orbital sander.
Although the sander made inroads into the epoxy, it made far deeper inroads into the adjacent (soft) ply. I found it impossible to achieve a really smooth, flat finish to the joints (the paint will take no prisoners!).
Enter stage left the trusty block plane.......
I found that if I planed the epoxy (heretic?) down to the level of the ply prior to sanding, the resulting joint was flat and smooth - but it does blunt your plane fast.
It's a small thing but for me made a huge difference for me
Hope you find my continued ramblings helpful
Cheers
Simon
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Anthony, you haven't told us which boat you are building.
BR17. :)
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Following up Simon's kindly-provided link to medisave, I was amused to see, having bought tongue depressors, 50 ml syringes and small room thermometers, that the 'other people who bought this item also bought....' links that automatically come up indicated, apparently, other people buying the same three items. There's no immediately obvious connection between them in medical practice terms. Could it be that boat builders are stocking up??!!
-- Which means, incidentally, that I now have more 50ml syringes than I am ever likely to need myself. If anyone else would like some (I can happily part with 30), for filleting etc, at bulk-buy price (I haven't worked it out yet, but it's something like 75p each) + postage (they're light)), send me your name and address in the personal message slot of the forum, and I'll willingly send.
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Following up Simon's comments about epoxy beads on scarf joints, I may be wrong but I think that particular smoothing challenge is one for you guys building ocean liners - I mean 17 ft boats. For my Storm Petrel at least (and I very much hope the same will apply to the Trouper), all the panels/strakes came full length in one piece, including those lovely hardwood sheer strakes.
However there are always challenges with epoxy bumps of various kinds, and my 'secret weapon' was a tool that I don't think is around any more. I still have it, I can't remember where I got it, it hasn't worn out but I have searched high and low for it (in case I need to replace it some time) without success. I don't even know what it is called. It's a bronze-coloured metal disc on an arbour for use in a drill. It is rigid enough not to need a backing pad. The surface is embedded with what I think must be diamond 'dust'. Used with a steady hand and a light touch, it whisks away unwanted bumps down to the level where one can sand smooth without the sort of sander problems Simon describes. In the shops/catalogues it seems to have vanished.
Doing some research on planes, I wonder whether a chisel plane would be handy for this sort of smoothing. I've never used one: does anyone have any practical experience? It is intended to smooth down to a surface without gouging or spoiling the surface. It would need to be kept sharp, like Simon's plane.
Anthony, do I detect some reticence in saying much about your project, because I believe you are the first, kit-wise - ?! Some time you and I must exchange experiences of squeezing a kit out of a small business VERY busy with building actual boats. Anyway, I hope your build goes well.
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Some reticence indeed, because didn't want to embarass Matt or annoy other members with "I've just bought a BR 17 kit" when they haven't quite been announced on the forum. Hence my comment on the BR17 thread.
I was actually going to buy a Storm 17 kit, but Matt didn't have one available for a test sail in mid October, so we test sailed his BR17 and decided it was worth the extra build effort and cash.
I've also not had much to say since I haven't even unpacked the kit yet - I went down with a shocking cold the day after we picked up the boat, and I have only just managed to get the garage sorted to the point that I am ready to start unpacking. I will be documenting the build on the forum. My insurers want a photographic record anyhow.
Interestingly on the BR17 Matt has dispensed with scarf joints on the panels in favour of interlocking fingers. I guess this is only viable with CNC cut panels. You will see how they turn out once I get started - the first real job is to join 18 pieces of ply into 6 long planks.
I think I'm actually the second customer for a BR17 kit, but I'm possibly the first to announce it on the forum.
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I'm intrigued by the use of interlocking finger joints rather than the usual scarphs. Are the joints reinforced with fibreglass or do they just rely on the very long glue line for strength? Do you bind the panels together with ties or are they just butted tight to each other as the glue sets?
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Julian,
For details of the finger joints see my other thread. The bottom panel gets coated in glass cloth and epoxy, but the side panels don't. The first finished finger joint seems very firm and strong.
Cable ties are used where you would use wire ties on a Storm Build to join the 6 long planks together to make the hull, though of course on the BR17 there is a 7th plank for the transom.
Anthony
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Anthony,
What swung you in favour of the BayRaider. Its a decision I'm trying to make. Hopefully will be seeing Matt at the London Boat show to confirm which one I want.
Clem
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Hi Clem,
Several factors swung it. I'm building the boat for us to use so I wanted confidence that I would enjoy sailing the finished boat.
We couldn't test a Storm 17 in October when I first got interested in building a Swallow Boat, but Matt kindly took us out in his BR17.
Water ballast was a big plus for my wife who isn't keen on unballasted boats (we've previously had various bigger boats up to 32 ft).
The transom design means that there is a lot more beam carried for more of the length and so the BR17 looks a lot bigger and more stable (though in reality it is only a few inches longer than the Storm 17).
The outboard well is a much better design, located on the centreline, forward of the rudder.
Thanks to the foam buoyancy in ballast tank (see Julian's post on my BR17 build thread) the cockpit sole is always above the waterline, even with the ballast tank flooded. It's self-draining rather than self-bailing.
The scarf joints on the major planks look like a really hard job on the Storm. On the BR17 you get finger joints instead, which I think are less daunting, but not necessarily quicker due to all the sanding to make a snug fit. See my "first finger joint" thread and you'll see what I mean.
The major downsides of BR17 vs Storm17 are cost (bigger boat plus false floor => more materials) and increased build time. And the fact that there aren't many home builders out there to share design-specific tips (though Julian from Denman Marine in Australia has been a huge help so far.)
I hope this helps in your decision.
Anthony
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Thanks Anthony, sounds like you went through the same thought processes I am, the only difference is my wife is unlikely to ever go aboard as she is not keen on anything smaller than a cruise liner.
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Back to the original topic of this thread, I've bought enough peel ply to do my BR17 (bottom panels inside & out and all taped seams)
As I understand it, for hand (non vacuum) layup, the procedure is to spread thin epoxy over the job (using a small roller), apply glass cloth, stipple and smooth with brushes and more epoxy as necessary to wet out the glass cloth, add peel ply and apply more resin with a roller to wet out the peel ply.
Is that the right method? Or can I omit the stipple step and just roller over the top of the peel ply?
Anthony
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There's no merit in adding resin on top of the peel ply, ideally you want the top dry (although it is inevitable that you'll have an excess of resin under the peel ply that will bleed through).
The most useful tool for getting as much resin as possible out of the glass cloth is a decent squeegee. West make some nice yellow plastic ones that I personally fine very good. The technique is to make sure there is a slight excess of resin on the glass cloth, then lay the peel ply, then work the resin out of the cloth, starting from the centre and working towards the edges. You need to take care to not let the glass cloth get resin starved, but unless you use lots of pressure on the squeegee this isn't very likely. What you will most likely find is that there is more surplus resin in the glass cloth than you would have thought.
I have found that it helps to smooth over curved surface with a gloved hand after going over it with the squeegee, somehow our hands are better at smoothing things out than a tool.
One important tip, make sure that the peel ply has no creases in it from being folded before laying it on. I always keep peel ply carefully rolled to avoid any creasing.
Jeremy
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Jeremy,
Thanks for the very helpful tips. I'll try to get some photos of doing the job so I can put them on here.
Anthony
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Note to self, and anyone else following this discussion:
Working alone it takes a good 2 or 3 hours to wet out the glass on the bottom panel of a BR17, and if you wait until you've finished the resin at the end where you started may have kicked.
I think it would have been better to lay the peel ply in approximately 1 metre squares or thereabouts as I went along, rather than going for a complete sheet once I'd finished with the glass cloth wetting. I'll try this on the other side.
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I always use 206 slow hardener for big jobs like this. It takes around twice as long to start kicking off as 205 and in warmer weather it gives you a much longer working window.
The downside with 206 is that it does take a lot longer to fully cure, in my experience, particularly if the temperature drops overnight.
You can buy the hardener separately, so a tin of 206 that you just use for the slow jobs may come in handy.
I'd avoid using small squares of peel ply if you can, as you will find it hard to pull off and you risk leaving peel ply fibres embedded in the surface at the edges. It always seems to work best if you have a healthy peel ply overlap around the edges, so that if it does start to tear when you pull it off you have another bit nearby that is big enough to grab and limit the tearing.
Jeremy