Thread: Another OZ MK2 PDRacer build in Sydney "Wood Duck"

1. Looking down the ridge line at the layer of glass rovings and seventy filler blobs, plus a filler strip to supplement where the plywood manufacturer had already filled in a defect





2. More glue! I added a third layer to the "trifle" that I had been carefully building all morning. This acts as the ridge cap, and it is the bit that will be sanded: and I didn't want millions of tiny glass particles flying everywhere





3. Glue/filler ridge-cap at the other end: I used a zip-lock sandwich "piping" bag for this process





4. Tape removed and the glue kneaded into shape. I left the glue for a bit while I did some work on my then-current Oz Woodwork Forum posts, and came back and worked the stuff to remove holes and fill in/form the peak. A final pass with a meths-soaked piece of paper towel finished things off to the stage that you see here





5. Partially formed "ridge cap": note the filler blobs. Once these have all set solid I'll sand them back using a cork block and 80-grit sandpaper, then add the final piece of the puzzle: a strip of 50 mm-wide glass tape over the lot





6. Roof with screw-holes filled and most of the work done on the ridge cap (except for sanding and addition of the glass tape)





7. Another view of the roof - awaiting the final touches to the ridge-work





8. Sanding back the glue-bead, to from the final ridge shape. Note the two sanding directions - each along the grain!





9. Glue on one side only - in this section. This is because of a difference in levels of the top edges of the two panels. This changes along the length of the roof until both sides are about even





10. One side sanded only...





11. Other end of the roof, where the two sides of the peak shape are roughly the same (depending on the shape of the board at that point!)





12. Roof, looking along the completed ridge-line. The not-very-hard-working long Perma-Grit block and the very hard-working sanding block are having a rest (especially in the case of the sandpaper!)


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It's getting there - slowly. I am at least up to date with all the snaps and activity on this thread, though ;). The ridge cap needs to be rounded over now so that the glass tape will conform to it - it wouldn't like the current fairly sharp edge as it is at the moment. After that, I'll pop the tape on and fill the weave and make sure that the edges of the tape are well and truly buried in resin! I'm going to give the first coat of undercoat a jolly good sanding to remove all vestiges of grain - or I might use the sanding sealer, if I can excavate it from the bottom of one of the teetering piles of junk where it is no doubt buried. That's still a way away yet, though. So much for the "throw-the-frame-together-and-slap-a-bit-of-paint-on-in-a-weekend" claim that I made a few weeks ago!

What a busy little bandicoot/beaver/mole/weasel/whatever I am at the moment...

1. It rained steadily all morning - and it kept up for most of the rest of the day, too. The raindrops here are more obvious in front of dark objects such as the tree trunks...





2. Ridge sanded down into a gentle curve; with a few deep scratches across the grain in the process :(. On the positive side, I'm not doing a clear finish :))))





3. Starting to tape the "chine": I unrolled between half to a whole frame's-width at a time, and brushed then stippled the resin on





4. Close-up of the beginning of the taping run





5. A couple-of-frames-and-a-bit's-width





6. Full length. The patched holes on the sheet extensions were gang-sanded with the long Perma-Grit block - which made that very quick! The new, darker patches on the extensions are where I've squeezed some WEST+BoteCote high-strength powder glue into various part-filled (after sanding) - and unfilled - holes





7. Close-up of the taped front end. Another item to tick off the list, although I still have a bit of weave-filling and sanding to do with the tape. The tape conformed nicely with the gentle curve across the centre of the roof :). Note that there was very little resin that didn't soaked into the cloth


Follow this link to my Flickr account. Watch out for Mr Snappy - he's very cross because I didn't take him sailing on Lake Macquarie on Saturday. Sorry, Mr Snappy, you can come along when we re-launch the 'Duck, promise :).



Whew! I feel a bit cross-eyed at the moment. I think that that might do for the day, unless the resin has gone off enough to put another single coat on after dinner. It's not as fraught a process as glueing, so I should be safe. Ho ho.

After a long slog writing this post the browser arbitrarily decided to junk the entire page - and post (twice), so I'm back to the beginning and in an even less good temper than I was in. A lot of the stuff dates back several days so I've probably forgotten a lot of it.

I've been fairly quiet of late as I've been fighting off a cold - and battling with glass-tape selvedge. I was expecting that the tape was going to be difficult, and it, um, didn't disappoint :(.

A thought that I had about the tape was that the weft edge-loops of the glass fibres have a large radius - much larger than those of other fabrics such as cotton, wool, etc. - and as such trap a large amount of resin. The glass fibres being less dense than the resin, they float to the top of these droplets, thus becoming raised above the general level of the tape. That's my little "theory" of the moment, anyway. This certainly is a good case for using the toilet-roll method of soaking up excess resin. I must confess that I didn't do that on this occasion. More fool me...


1. Battling with the tape selvedge (see aslo the previous paragraph) - the roof-long trough to cut down below the raised tape edge. and the tool used to create it (RH end of roof)





2. Perma-Grit file used to gouge a trench down to the glass: and in some cases the wood!





3. Close-up of the gouge. The glass tape can be seen here quite clearly





4. Trough vacuumed clean and ready for some resin





5. Trough with glass fibres burnished down into very slightly sticky resin with the side of a paint-brush handle. It's a bit difficult to see the glass at this point in this photo, although it was visible to the naked eye. WEST resin was used in this instance in order to soak into the glass as quickly as possible





6. Resin-filled trough. Note that the roof has been propped up so that this side was as level as possible - to allow the resin to stay put in the trough!





7. Close-up of resin-filled trough and some air-bubbles from the bared timber at the bottom





8. View of the resin-filled trough. What looks a mess at the moment will clean up fairly quickly after much effort with sandpaper and Perma-Grit blocks - and lots of elbow grease!





9. The peak, filled trough and the filled screw-holes - after a lot of sanding





10. After some vacuuming: looking a little bit better





11. Yet another coat of resin...





12. Close-up of front gable-end. This looks very much like eucalyptus plywood to me


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This has really been testing my patience, and I have also been experiencing a tiny bit of claustrophobia in the cramped conditions. More later...

I decided to tape the inside of the roof joint after some deliberation over it. It will get minimal resin and NO sanding:


1. Roof inverted to remove the blue tape and inspect the roof-panel joint on the inside. I blocked the "V" at four points in an attempt to keep it from wobbling about too much





2. Yes, it's blue tape…





3. Overview of roof joint, tape removed





4. Some carbon fibre showing through






5. More carbon fibre. That was quite a gap between the two panels at that point <grumble>





6. Another segment of the inside surface of the roof panel joint





7. The gap between the panels doesn't seem to have been quite as bad at this end…





8. More glass tape <sigh>. This is going to get minimal resin - and no sanding!





9. Internal segments of glass tape, resin applied. WEST 105/207 was to get the tape saturated quickly. This time, I mopped up the excess with toilet paper torn off the roll (see previous post!). Note that I used up the resin when it gelled too far to work easily into the cloth by applying it to the "skids" :)





10. Front end, tape just glued on with resin





11. A reasonably even bit of tape-glueing





12. Rear end, showing glued-down tape - and some carbon fibre having escaped from the joint


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In my experience with working with epoxy and glass tape, it seems to me that the best approach to prevent the tape floating is to wait until the first resin coat has set completely before adding any more resin. Even at the almost-not-tacky stage new resin seems to rapidly dissolve the gelling first coat - and the glass lifts immediately. I know that I’ve had tape dead flat on the timber, only to find when doing the sanding at the end that the tape has bubbled and lifted; this also occurred with the mast. Not the foils as I remember it, however: I'm pretty sure that I let the first resin coat set before adding any others - and the result was perfect (and there were no tape selvedges to contend with either, of course ;).

Once I've dealt with the inside of the ridge-join, I'll flip turn the structure over and finish off the ridge-cap. After that, some tidying up of the end-plate stiffeners. When that's all done - painting :).

Just need a mast step and some rudder pintles!

MIK

Originally Posted by Boatmik

Just need a mast step and some rudder pintles!

MIK

Hehe, too bad the rocker is at the top.

Heh :).

@Mik: it would be a wee bit unstable, and the "dovecote" holes are a bit high for self draining - or a bit low for wave clearance ;)

@woodeneye: pity about that! I could always sheet the bottom, cut out a hole for the cockpit (as is done into a fully sheeted fuselage in many model aircraft) - and sheet over the "dovecote" holes (see comment to Mik ;). It still wouldn't be the true rocker of the boat, but it would be closer!

Cheers
the alex.

Another of my very infrequent photo-free posts! I suspect that people don't want to see yet another snap of resin on tape - which is what I did this morning, after rubbing off the stray strands of glass fibre with some 80-grit paper. I also dealt with some glass bubbles and tape-lift around the butt-straps. While I had a block-full of 80-grit paper for the butt-strap ends (as well as the small strip of same paper for the whiskers), I ran around the bottom edge of the roof panels to take off the sharp 90 degree edge, replacing it with more of a 45 degree bevel. I'll do the same to the top edge at some point when the structure is turned over (this arvo for the latter, I hope), and round off the sharp panel corners a bit.

Having cut into the glass tape in spots along the ridge cap when sanding it, and the fact that the ridge is fully exposed to the elements, I want to make sure that the glass is fully waterproofed and sealed before the undercoat goes on, and no wicking of water (via that source) can occur. There is a sealing coat on it now, so I intend to finish it off - fingers crossed - with a final layer of BoteCote, which is nice and thick and will allow for careful sanding.

Once I do turn the roof upright (again), I'll place it on blocks under the end-plates so that I'm not crawling about the floor with my beak to it quite as much as I have been doing.

I'm hopeful that I'm into the final pre-painting stages, and with a bit of luck may be applying the first coat of undercoat top and bottom tomorrow...

Judging by this afternoon's efforts I don't think that I'll be putting the undercoat on until Wednesday (a busy day with a late evening) or, more likely, Thursday.

Snaps again, though:

1. Roof with "ridge-cap" and panel sides resin-coated





2. Rounded-off corner: flat coarse Perma-Grit file. This snap is a bit fuzzy as the camera - depsite having its focus area set at the centre of the frame - decided that the end-plate support (bottom LH corner of snap) was much more interesting...





3. Close-up of rounded-off corner. Very quick and easy to do (rounding the corner off, not taking the photo: in fact, taking the snap and getting it right was actually harder!)





4. Rounded-off corner: sightly more in focus


Follow this link to my Flickr account: watch out for the wet resin!



I've got a more than few deep dents to fill in the top-sides of both roof panels: as a result, no doubt, of the thing being bumped around on a dirty floor. I found this out while doing the edges: and the ridge wasn't immune to damage either. Hence the revision of the date for starting painting. There's always something...

I knocked off the weather-proofing of the end-plates - filleting ;) - last night, and started the shaping work on the end-plates. "Meranti", a.k.a. "Pacific maple" is a very easily-worked timber - a number of species in Genus Shorea: of which the vast majority of known species is critically endangered, see link...

1. Initial glue bead before forming, applied using a zip-lock piping bag. Note that the central vertical fillets were applied and formed many days ago, when the end-plate stiffeners were glued on





2. Glue-bead after forming into a fillet, using the unmodified end of a tongue depressor as the working radius. I didn't manage to get back to final smoothing as it was rather late in the evening, so that had to be done the "hard" way with various Perma-Grit files when I was rounding off the edges of the frame (to prevent splintering, allow easier water runoff, etc., etc., etc.)





3. Roof with resin trimmings, "final" patches, etc. The edges of the roof panels where some splintering had already occurred got a dose of glue on top of the still-a-bit-sticky resin





4. Round notches filed into the corners of the front end-plate framework: the first step in this shaping process





5. Long edge between notches nearest the camera have been rounded over and some of the glue has been tidied up. The notches, of course, are no longer there. The rounding is a bit hard to see on the horizontal element (only half of it has been done in any case), but is more noticeable on the vertical ones. The centre-post has been half-shaped at this point. Note the support blocks - actually more stable than my usual attempts at such things ;) - and the absolutely essential head-torch


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There's lots more shaping to be done - that shown above only scratches the surface, so to speak - so I don't think I'll be getting anywhere near the paint pots tomorrow. Maybe Thursday. Or Friday.

Hi Alex
You might want to think about chamfering your external framework to prevent water pooling there.
Especially if you aren't going to encase it in pox.
Incidentally, the rocker isn't at the top.
What you have there is a reverse sheer.

Ha - that means that I'm quite literally off my rocker :).

The current rounding over has a radius of about 7 or 8 mm, leaving a ledge of about 10 mm between the bottom fillet and the start of the radius. I guess I could get the spokeshave out (or the wood rasps) and cut the ledges down - or add back some of the weight that I have removed in shaping by slapping a bit of 'pox on the "feet": a small addition of weight for a large gain in waterproofing. Or, I could shave the top surfaces of the feet down and coat with resinI have also been seriously considering a single coat of WEST over the entire top surface of the roof panels only for the same reason.

The boss and I did a trial lift of the structure - in cramped and difficult circumstances - after the roof had been permanently welded in place - and it was easily manageable despite the weight. And it won't be being moved further than a trailer's-width away from the boat in any case.

I also considered casing the whole endplate structures in plywood, but it started to get complicated around the ventilation "bird doors" and began to look like a lot more time, effort and materials (I would have had to have bought more plywood) than it was worth, so I abandoned that idea. That could be retro-fitted down the track if I ever considered it necessary.

Speaking of resin - and tempting fate - I haven't seen any fish-eyeing in my use of BoteCote (without powders) on this structure. Having said that, of course, I'll now get nothing but fish-eyes, all goggling at me and saying "ha ha" ;). Superstition aside, it is intersting to ponder why the fish-eye hasn't been appearing: better wood hygiene, perhaps, and the final ridding of silicon from the workswamp? Curious.

Cheers,
Alex.

After a bit of pondering b.o.a.t.'s advice, I realised that the chamfer didn't need to be extreme: just enough to prevent water from forming a pool under surface tension. All it needs is a gentle but sufficient slope that discourages the latter behaviour.

The following documents what I came up with:

1. An array of choices: I tried the Vertias "scraper" (with the large black handle) first, then switched to the sharper of the the two "Two Cherries" (Zwei Kirschen) chisels - working against the grain on both occasions.





2. Chisel making the first series of cuts chops splits at approximately the angle that I stayed with. I avoided the glue line (just) with the chisel, and dealt with that with the flat coarse Perma-grit file and sandpaper





3. The "finished" chamfer. I took the material removal back to the line of the bottom edge of the fillet, re-make the roundover at the front edge, and smoothed the resulting camber from back to front off with 80-grit sandpaper





4. Another view of the new "sill". Water shouldn't pool too much on this. Without 3D the new slope is rather hard to see


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Having got one of the four-and-a-bit horizontal "sills" done, I left it that exercise to do some glue-sanding elsewhere and ponder this a bit more. Thanks to AJ I think I'm on a better track here :).

Thanks, AJ!

Pushing the window analogy a bit further (via the sills), I'm going to take aleaf out of the glaziers' handbook and run a second straight (un-radiused) fillet over the top of the existing population of horizontal curved ones. The new fillets will finish "over the edge" of the new chamfers, thus removing most low points for water collection, and the lower edge of the new fillets will most likely be very gently blended in with the sloping "sill". The whole lot will get a coat of epoxy once the fillets have set.

I'll use sanding filler for this as I have been chewing through the glue powder at an alarming rate - and a good proportion of that has been wasted! Which means that I need to get the sieve out and get rid of the moisture-induced lumps in the sanding filler powder.

Since the chisel I'm using is pretty sharp (amazingly), I've been chewing through the sills at a great rate, and have only one segment left to do.

Barely fifteen minutes after writing the above - and ten minutes into a practice session - a horrible stomach bug hit me like a freight train. I spent yesterday and most of today in bed, and am still not feeling much like doing anything except read - certainly not anything that requires precision handling!

More when I've recovered and got something complete, whatever it was I was working on before the bug struck - chamfering the top surfaces of the end-plate feet, I think.