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

Well, there are different fillers for different purposes. The fibers and milled fibers are to add strength. Then there are are the phenolic resin ones and similar that just make it fluffier to make it easier to sand. Then the other ones are to increase the viscosity (like the fumed silica). Of course, I have soaked up this info that I just gave up on. I really prefer the pre-mixes. They are much easier to deal with and I don't have to work to get them mixed. Actually some of them like the silica ones are supposed to be pretty nasty if inhaled. I just don't like taking all the time trying to get them mixed in.

It's funny, when I snap a stick, I just toss it and make a new one. The offcut always gets used eventually. Different strokes for different folks I guess.

The other thing about bending sticks into place concerns how you do it. I've noticed over the years that an experienced builder will massage something into place that a novice will break (or fail to get into place). The most obvious example of this was watching a bloke fitting planks to a lapstrake hull - we novices were having all sorts of trouble and it looked like the plank was the wrong shape but Moose just laid those massive paws on the thing and turned to wet spagetti and slid into place. I had similar experiences with Redback where planks would intially refuse to go into place until I'd worked out just how where to apply the force. When bending things like inwales and the like into place, you develop a feel for the timber and can predict when it's going to go 'bang' ... I know this because I tend to think 'it's about to go' and then give it the extra shove thereby hearing that bang

Richard

Here are the answers to the quiz. I was going to also put up some more photos, including that of the "first option" attempt to fix up the mess I've made of the rear of the port side deck, but some pulled inter-costal muscles are nagging so badly that I'll leave that until tomorrow in a separate post, and have an early night + painkillers. But to those who took an active part in the quiz,

C o N G R A T U L A T I O N S, E V E R Y O N E ! : )

Hope you liked the "prize" :).

BTW, I couldn't do the whole colourful thing above in all caps, as the forum parser kept converting everything to all lower caps if I did so, and could only get around it by inserting at least one lower case letter. And I couldn't work out or otherwise discover a BBCode to force all caps ;).

Photos:

1. Mystery Object # 1: this is a support bracket for the upper cross-piece of F1! People got so close, "but still no cylindrical smoking fing", apologies to Terry Pratchett :). Explanations, etc., after the photos...





2. Close-up of the support bracket





3. Mystery Object # 2 - a complete conceit! As you can see, this is totally parasitic weight/drag...





OK, so why a support bracket for the F1 upper cross-piece when it already has had two screws added at strategic points? Well, as you may remember, I wasn't convinced 100 % by the addition of these items, and when Martien - who is an engineer by training - was around one day, we were discussing this. He was of the opinion that a pair of wooden brackets between the two cross-pieces, at the points where the screws were added, or even on the hull sides nearby, would possibly have added much greater support and strength to the cross-piece. I muttered about extra weight, but had to admit that it was something running about at the back of my own mind. We eventually thought that a compromise of having a bracket under the centre of cross-piece would be useful, and not add much more weight, while at the same time complementing the screws. It was also agreed that it wouldn't look aesthetically out-of-place (remember also that the centrecase top cleats were enlarged, and that one has stuck).

I used the lightest piece of straight-grained oregon that I could find in my scrap pile, and hacked up the resulting bracket using a Japanese saw and some sandpaper.

The small piece ("Mystery Object # 2") was a perhaps silly addition to balance the new bracket, visually, but since the front bracket was hiding two screw holes (actually, four, after moving the screw positions after adjusting the case height), I thought that a strip of oregon at the back would be effective in hiding the two screw holes at the back of the case, as long as the pieces was thin, light and nicely finished off. It also sort-of looks as though part of the case is protruding out of the frame. Anyway, if I find I can't live with it, I'll grind it off. Note that I have yet to add the resin triple-cpoat to either part.

As can be seen from photos in previous posts, the top and bottom edges of both parts were rounded over to accommodate the fillets, not being in a mood to take to the fillets with a chisel when there was enough room to allow the cross-piece bracket, at least, to supply adequate support to the beam. Both parts were also radiused along their long edges, to tidy them up and let them fit in with the way that the rest of the frames' and cleats' visible edges are finished off.

So there you are. If I were doing this again while building F1, I would probably also add brackets on the inboard edges of the outer panels as well, again using light, straight-grained oregon, and lose the screws - which would also have meant, in my case, not spending hours on hand-fitting those plugs!

I hope to have increased the support to the cross-piece without too much of a weight or aesthetic penalty, especially since there is a 3 mm strip of timber running the entire width of the cross-piece which is glued on using only neat 2:1 BoteCote (that is a post-hoc justification, not a design decision! ;), see Daddles' comments about resin vs glue above. I also hope that I haven't upset Michael too much, or stirred up a hornets' nest, either!

By the way, the jiggery-pokery with the port carlin has worked! I removed the clamps around noon, gave the piece of carlin poking out over the stern an experimental and gingerly tug, and it remained in place. It is also sitting in the correct position wrt the diagonal cleat extension line, which was the main reason for all the associated conniptions.

Photos and discussion of the carlin - plus some extra photos of the new bracket - later :).

That crossbrace I put in the wrong way Mine is vertical.....

Got any more wood left over???!!!

Originally Posted by dkirtley

That crossbrace I put in the wrong way :) Mine is vertical.....

Hi David,

Just put it down to greatly increased beam strength - without the (perceived) need for brackets - or screws, for that matter ;).

Cheers,
Alex.

It would also be a great place to have a tether for the daggerboard or a fender ready for either side. Another to stake down the ice chest (esky for you antipodes

Originally Posted by woodeneye

Got any more wood left over???!!! :)

Hi Bruce, If you are referring to me, then no, I don't have much oregon or ply left over, and certainly not enough of either the make either parts from new! Good oregon is as rare as hens' teeth here in Oz now, and all mine came from left over stock shoved up the back of a timber supplier's, and which supplier is not getting any more. Plantation Pinus radiata has squeezed Douglas Fir right out of the market - unless you are quite wealthy - and I'm not! Having said that, I was fortunate to get some of the oregon that I did, since one large length was very dense and well seasoned: nice and strong, few knots and straight-grained. I didn't have enough for the carlins, sheer clamps or chinelogs, which otherwise would have come from that length - and the port carlin would have have been less inclined to split under my "tender" ministrations ;).

And to think that I gave my brother-in-law half-a-dozen 4 " x 8" x 18 ' beams of the stuff a couple of decades ago when I was "de-1970s-ing" a house in Adelaide... Still, it would have been quite a bit of trouble lugging them over here and between dwellings in Sydney, let alone storing them. And the BIL lives in the country and has lots of storage space. Maybe I should get in touch with him and see if he still has those beams;).

Cheers,
Alex.

Originally Posted by dkirtley

It would also be a great place to have a tether for the daggerboard or a fender ready for either side. Another to stake down the ice chest (esky for you antipodes ;)

Funnily enough, I thought of drilling a hole to tie the bailer tether to, but decided that it would weaken the bracket too much, and it could be tied around one of the three cross-pieces anyway. But I like the esky-tether idea - for the Bundaberg Ginger Beer and Peachee (latter is very hard to find!) that I love to consume (the medication I'm on more-or-less permanently doesn't allow for alcohol anymore...).

Originally Posted by AlexN

Hi Bruce, If you are referring to me, then no, I don't have much oregon or ply left over, and certainly not enough of either the make either parts from new! Good oregon is as rare as hens' teeth here in Oz now, and all mine came from left over stock shoved up the back of a timber supplier's, and which supplier is not getting any more. Plantation Pinus radiata has squeezed Douglas Fir right out of the market - unless you are quite wealthy - and I'm not! Having said that, I was fortunate to get some of the oregon that I did, since one large length was very dense and well seasoned: nice and strong, few knots and straight-grained. I didn't have enough for the carlins, sheer clamps or chinelogs, which otherwise would have come from that length - and the port carlin would have have been less inclined to split under my "tender" ministrations .

And to think that I gave my brother-in-law half-a-dozen 4 " x 8" x 18 ' beams of the stuff a couple of decades ago when I was "de-1970s-ing" a house in Adelaide... Still, it would have been quite a bit of trouble lugging them over here and between dwellings in Sydney, let alone storing them. And the BIL lives in the country and has lots of storage space. Maybe I should get in touch with him and see if he still has those beams.

Cheers,
Alex.

Hi Alex, I'm sorry, I was just having some fun when I made that comment, and it was only because we all gathered that the pieces you added are not part of the original plan. In other words, "were you looking for more places to attach some more offcuts?" was the real meaning behind that comment. I have a bit of a dry sense of humour that often gets me into trouble. I'm not really after any wood but appreciate your reply anyway

Alex in years gone by the brace is something you would attach the bottle opener to, as in long necks.

Originally Posted by woodeneye

Hi Alex, I'm sorry, I was just having some fun when I made that comment, and it was only because we all gathered that the pieces you added are not part of the original plan. In other words, "were you looking for more places to attach some more offcuts?" was the real meaning behind that comment. I have a bit of a dry sense of humour that often gets me into trouble. I'm not really after any wood but appreciate your reply anyway :)

Hi Bruce,

No probs :). I have a tendency to not notice other people's senses of humour ;). I get into a lot of trouble with comments that are meant to be funny but are interpreted as - well, insults!

I have way too many small offcuts from this project, which can be viewed (well, it is by me) as being a waste, but I wasn't looking to use them up for the sake of it - I'm actually trying to keep the weight down!

Cheers,
Alex.

OK, this post should tidy up the bracket photos, and a good thing, too :). Interestingly, there hasn't been any adverse criticism of my addition (yet ;). I am really interested to know what everyone thinks...

Photos:

1. For the curious: how the bracket was held in place while the glue set - blue tape! In hindsight, packaging tape would have been better as it wouldn't have broken so easily when tensioned. Still, the blue tape worked, and that's what matters :)





2. Two loops of blue tape wrapped around the centrecase assembly to hold the F1 upper cross-piece support bracket in place while the glue set





3. Grubby-looking cosmetic part. Well, the tape's grubby: the wood isn't :). The tape did nothing to hold this part on, of course: the part was just stuck on with brute force and left to take its chances





4. The blue tape was carefully eased off the cosmetic part before the cross-piece bracket was relieved of its tape restraints





Right, that's done - now on to more recent stuff!

Hi AlexN,

The 2 mystery objects and their placement are not included in any plans or updates that I have been able to see for the Oz Mk 2 PDRacer, so are they your own custom mods ?.

The front piece certainly makes the centrecase look much more robust, but I am uncertain if you hit any submerged obstacles/sandbars with the centrboard whether it will make any practical difference to the strength of the centrecase, or for strengthening any removable seat mounted on the centrecase.

Of course you may have made the mod for some other reason, that I am unaware of.