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

Glassing the cockpit floor, part 3...

I spent most of today's work period on the boat scrubbing away tidying up the edges of the glass cockpit floor panels, all now nicely stuck down and set :). New, sharp sand-paper helped cut away the glass and resin quite quickly, although I had to replace the paper at regular and frequent intervals.

By the way, this is one of those posts where the captions get a bit lengthy...

*** Note: All photos shown here can be viewed at various sizes via my Flickr page. Here ends the contractual obligation notice ***

So, some snaps:

1. Forward cockpit section - main glass floor panel, trimmed to fit and test-laid in place





2. Starboard outer glass floor panel for the forward cockpit. The outer panels were glued down and the resin allowed to go off a bit before dropping the large piece (carefully) in position and adding glue to it





3. Aft cockpit glass floor panel, trimmed roughly to shape and laid in position. The aft well only needed one piece of cloth, which simplified things markedly compared with the relative complexities of the centre and forward sections. View looking forward from the stern





4. Stern end of the aft cockpit glass panel. The aft section lay between the centre (easiest) and forward (hardest) sections in terms of ease of clean-up. The centre section panels were an almost-perfect fit thanks to all the hard work on the template; the forward section was the most difficult thanks to the two ridges created at the functions of the three panels, and the air bubbles at the three changes of direction over the chinelogs, caused in part by the relatively large curvature of the chinelog, and in part by the rather large cloth excess at the outboard ends of the cloth. And also the builder not going back to check half an hour after patting those bits down!





5. Starting to glue the aft cockpit floor panel down: about half a dozen splotches of resin just behind F2 anchored the cloth in place (more or less ;)





6. Around a fifth of the area glued down. The cloth was a bit more mobile in this section probably as a result of applying just a bit too much resin, and I had some fun with bubbles, at least until got to the surface with the toilet roll. That fixed 'em, but took a bit longer than the preceding three sections, a. because a bigger area being covered in one hit, and b. using a bit more resin than necessary. Still, it all got smoothed out in the end...





7. ...and looked like this: the aft section just after the toilet-roll treatment. You can see here that the panel was left quite a bit oversize - sharp sand-paper was my friend here ;). After viewing the large-sized version of this photo, I've been starting to think that all the effort that I've put into the Eurolite ply has been worth it





8. View of the newly glassed aft cockpit floor, looking aft: excess cloth very much in evidence. Gaboon or Pacific maple ply would have been quicker, easier and cheaper - but the light colour and the subtle(-ish) grain of the poplar ply in contrast with the PM ply is quite effective and pleasing :)





9. Overview of the aft and centre cockpit sections with their new carpets. I've still to sand off the bits of excess cloth and resin in this photo. The dark patches on the side decks are thin coats of resin, used to fill up holes where I was a little bit too enthusiastic - and heavy-handed - with the sand-paper, in attempting to remove the evidence of poor technique in applying the temporary screws. The foredeck (not visible here) was the worst affected...





10. Most of the three cockpit floor sections, after a lot of use of sand-paper. I'm ripping through the stuff - so much so that I've had to order 12 metres of various grades, before the Christmas shut-down. Compare and contrast this photo with No. 8 above





11. Forward section cockpit floor, glassed and cleaned up. Lighter patches are where I've been scrubbing with the 120-grit sand-paper; the odd patches in towards the centre were where some glass strands had got themselves inconveniently glued down to the top of the cloth (at least they weren't under the cloth!). I also cleaned up the excess resin that had dribbled down the cockpit bulkhead when coating the coaming, while I was at it





12. Close-up of the spots where the cloth hadn't been able to conform to the complex curvature sufficiently. The bubbles have been cleaned up with sand-paper - leaving shallow holes. I'm not too happy about that, but as I commented above, it's non-critical, and the holes will fanish with a coa (or two) of resin





I spent the second working block sanding assiduously away at the resin patches on the decks. While I was sanding off the glass along the bottom of the stern transom this morning, I noticed that excess resin running down the outside of the transom appears to have pulled the ply away from the top cleat - there is a gap of over 0.5 mm at its widest. This was either a dry joint to begin with (eek! - how many more of those are there?), or the force of the resin bending the ply was sufficient to break an already weak joint (see previous parenthetical comment!). Hmm...

Tomorrow: the fill-coats on the cockpit floor's carpets ;). And more sanding...

I look forward to looking at the boat in the flesh in a week or so Alex!

Best of the season!

MIK

Originally Posted by Boatmik

I look forward to looking at the boat in the flesh in a week or so Alex!

Best of the season!

MIK

Happy Christmas and New Year (and to everyone else too!), and I'm looking forward to your visit too, MIK .

Cheers,
Alex.

I applied the first weave-filling coat of resin this morning - it almost filled the weave up but not quite, so another thin coat will be added - later. Later, because the first coat revealed some bubbles in the aft section that I hadn't noticed before, and in fact may have been accentuated by the extra resin, something like what appears to have happened on the upper edge of the transom. I had a bit of trouble dealing with bubbles on the chinelogs and in the aft cockpit when the resin was still wet, so I'm not terribly surprised. I also found a large bubble that I'd missed when removing said objects from the chinelogs, so that will have to be dealt with at the same time as the bubbles in the aft cockpit.

I'll let the entire floor cure, then sand the whole lot with particular attention being paid to the bubbles, then fill by spotting (or patches with extra fiddling). After letting the spots cure, I'll give the whole floor its second coat, sand it smooth and leave it. I've got a door to straighten in the house, so I'll do that while waiting for the floor (of the boat ;) to cure. The hull bottom is sounding a lot "tighter" when tapped with the knuckles, suggesting that the added cloth has been useful in stiffening the Eurolite ply a bit more. The bottom sheet is, of course, covered on both sides with 1/2 ounce glass cloth, except for the three buoyancy tanks (which, it has to be said, are all smothered in thick layers of resin ;).

More sanding...and yet more sanding...and...

Fortunately, the bubbles in the aft cockpit floor carpet were full of resin, not air, so they were easily dealt with, as have been a number of stay glass strands littering the area. I've also been cleaning off the chinelogs and the fillets around all the edges - and that has been taking up all the time and the scrubbing. Not particularly hard, as the resin is stripping off easily, but tedious, as there is so much of it. I'm having a wee break to allow my fingertips to recover a bit...

Once the "mini-scuppers" are all done, I'll whizz over the rest of the floor with the cork block.

While I was out shopping yesterday, I acquired two 100 metre spools of "Guettermann" 100 % polyester "upholstery" thread ("Made in Germany") from one of the local fabric shops. The girl who sold it to me said that it was the strongest thread that they sold (I told her what I was wanting it for). The thread looks a little on the thin side, but I have to accept that she's right! At least until proven otherwise ;). I'm not worried about the strength of the thread, but the capacity that it might have for cutting itself free of the polytarp under strain!

Ha ha - did I say that I'd whizz over the rest of the floor with the cork block? Ha ha ha. Very drole. Very funny. I actually ended up hand-sanding the floor, and it took most of the afternoon. And the result is some rather sore finger-tips and thumbs. Oh, and a sanded floor: it's not perfect as the fill-coat was somewhat uneven in patches. I'm relying on the resin to fill in the remaining gaps; and after all - it will get sanded again, anyway!

I'll hoover up the snow, and coat the floor again this evening - or more likely - tomorrow morning. I dug out the sail pieces this morning, and will attempt to work out which is which (lug or sprit) and get to work on drawing the outlines of the pieces, if I can get the Boss to allow me some living room floor space ;). On the other hand, it might be better to wait until after Christmas...

That fine glass cloth really is very tricky - once it has been coated and sanded, it really hates wetting up again for a subsequent coat :(. The (second) coat that I've just put on is pulling away from the cloth in relatively large patches (2 mm x 5 mm in one case). In my view, any failure to wet is large! I vacuumed the (cockpit) floor, ran over it with the microfibre cloth, then gave it a good swab with acetone to remove any grease/oil from my skin that inadvertently ended up on it while sanding, before letting the resin anywhere near it. This also suggests that I sanded a bit too far between the two coats. Gravity is also helping to a degree, and the pull-aways are more prevalent on the fore and aft floor sections, where there is a more pronounced slope.

I didn't have to put a third coat on - I merely patched the "holes" with some drops of resin and a half-credit-card squeegee after the main body of resin had firmed up enough to resist the squeegee. Seems fine now :). So, apart from some final sanding, that's the cockpit floor finished - hopefully foot- oar- and esky-proof ;).

Glassing the cockpit floor, part 4...

I'm intending this to be the last of the photo essays on the pre-launch(!) cockpit floor ding-resistance "upgrade". After the final sanding of the floor (prior to varnishing it of course) I'm going to forget that I've done all this work ;).

*** Note: All photos shown here can be viewed at various sizes via my Flickr page. Here endeth ye contractual obligation notice ***

The photos:

1. Sanding all those fillets...





2. Resin bubbles gouged off the aft cockpit floor: 120-grit sand-paper used, as with the fillets





3. Centre-secton flattened, port side





4. Forward cockpit floor has been given the same treatment





5. Entire cockpit floor sanded smooth, down to a relatively (but not completely) even thickness. The brush on the centrecase has become a dust -brush ;)





6. "Snow" from sanding the starboard aft tank side face





7. Close-up of the snow





8. Centre and aft cockpit sections, final resin coat, bt before fish-eye patching...





9. Forward cockpit section, final coat, pre-patching





10. Starboard centre-section, final resin coat. The glass cloth is nicely invisible, all the weave-texture is just slightly apparent





11. Forward cockpit section again: post-spotting this time. The black spot on the RHS of the photo that looks as though it might be a fly - is in fact a fly. It dropped dead right over one of the fish-eye patches...





12. Close-up of one of the patched areas: a drop of resin per spot, plus the application of a half-credit-card squeegee





That's it for tonight - tomorrow's a day off from the boat, imagine that ;).

Happy Christmas to everyone :).

Will be interesting to see what the weight is with the extra glass. I don't think it will make a lot of difference to sailing performance, but it might make a bit when you have to lug the boat from the carpark!

The good thing about the PDR is the lack of bulk which is almost as important as light weight.

Best wishes
Michael

Originally Posted by Boatmik

Will be interesting to see what the weight is with the extra glass. I don't think it will make a lot of difference to sailing performance, but it might make a bit when you have to lug the boat from the carpark!

The good thing about the PDR is the lack of bulk which is almost as important as light weight.

Best wishes
Michael

A back-of-the-envelope calculations suggests that the increase in weight will be in the region of 255 g including cloth and allowing for sanding. My original estimate was based on number of pumps used - I forgot to multiply them by the actual volume of each pump (7.5 ml for resin + 3.75 ml for hardener). Since the density of the mix will be lower than the equivalent volume of water, the 250 g is arrived at by a rough estimate of 80 g per coat plus 25 g for glass less 20 g for sanding (very approximate!) giving 255 g. The poplar ply is also much lighter than Pacific maple ply. I'll do some more careful sums with measured densities tomorrow. But I can live with the added weight (1/4 kg; 1/2 lb) in any case, even with the extra
GRE on the hull bottom ...

Cheers,
Alex.

Here are some more figures, derived from my mini-scales and calculator:

1 ml resin = 1.0 g; 0.5 ml hardener = 0.4 g; 1 ml = 0.8 g

1 pump = 7 ml = 7 g resin; 1 pump = 7 ml = 5.6 g hardener

ratio resin:hardener = 2:1

1 coat:
8 pumps resin = 56 g; 4 pumps hardener = 22.4 g

total for one coat = 56 g + 22.4 g = 78.4 g

3 coats = 3 x 78.4 g = 235.2 g

Add approx 30 g for glass cloth (< 2 sq. m) = 266 g approx

less 20 g (?approx?) for sanding coats 2 and 3 = 246 g all up.

My initial guesses about the densities of resin and hardener proved to be wrong - the resin was denser than the hardener (by 25 %), and the resin had the same density as water (more or less - STP conditions don't apply, since the temp is < 25 degC and we're about 300+/- m above sea level).

So, compared with last night's estimate, I'm approx 10 g in front, which is not particularly significant one way or the other, and I'm still looking at around 250 g for the glass plus 3 coats minus what has been/will be removed by sanding. The estimate of amount removed is really a wild guess - some weight has to be removed, but until I do an experiment on a piece of resin-coated plywood sanded until smooth and weighed before and after, I won't really know. Or else sweep up and weigh what I remove by sanding the floor for the last time (prior to varnishing).

While at the In-Laws for Christmas, there was a flock of about a dozen wood duck on a roadside nature strip nearby. Not wanting to miss a golden opportunity, I took some snaps with the SX1 wound out to its full 100 mm (560 mm 35-mm equivalent) enabling me to keep a respectful distance. The lens' optical stabilisation was on as well: I've always got it turned on - for shooting, anyway ;). The results were reasonably good given the relatively slow shutter speed, my shaky paws, the moving targets, and the low light (heavily overcast morning). Quite a few of the snaps didn't turn out too well, because the subjects (a pair) kept moving about, as these creatures do. Also had the photo-review set for too long (i.e., for the not-very-fast-moving boat) and by the time that I'd got the shutter back the birds had often skedaddled.

I now have a number of images from which to construct a "cartoon" for one side of the sail(s) - the other side(s) will have the Puddleduck logo.

Oh, and I've got the sanding of the cockpit floor done, and am carefully scooping up the dust to weigh it - more on that tomorrow.

Originally Posted by AlexN

While at the In-Laws for Christmas, there was a flock of about a dozen wood duck on a roadside nature strip nearby. Not wanting to miss a golden opportunity, I took some snaps with the SX1 wound out to its full 100 mm (560 mm 35-mm equivalent) enabling me to keep a respectful distance. The lens' optical stabilisation was on as well: I've always got it turned on - for shooting, anyway . The results were reasonably good given the relatively slow shutter speed, my shaky paws, the moving targets, and the low light (heavily overcast morning). Quite a few of the snaps didn't turn out too well, because the subjects (a pair) kept moving about, as these creatures do. Also had the photo-review set for too long (i.e., for the not-very-fast-moving boat) and by the time that I'd got the shutter back the birds had often skedaddled.

I now have a number of images from which to construct a "cartoon" for one side of the sail(s) - the other side(s) will have the Puddleduck logo.

Oh, and I've got the sanding of the cockpit floor done, and am carefully scooping up the dust to weigh it - more on that tomorrow.

Hi Alex
A good feature that is great for shooting animals is the rapid fire setting. Because digital cameras are so slow to react between shots (compared to the old film cameras) due to the laborious file saving procedures, it can get you those in-between shots that are otherwise missed.

Almost there now I see Did you glass inside the cockpit for added non slip reasons, or for strength?