Thread: Hello, new GIS build by Simon in ST Pete FL

Originally Posted by Compass Project

I made Spruce staves and for kicks will be alternating staves with Western Red to get a nice contrast in wood types. I might try a spar with poplar and cedar. We'll see how it looks and works.
Clint

Hi Clint, I would suggest that you should rethink this thought as in my experience, WRC would be absolutely no good for masts. It has no "stretch" at all and it's short grain length causes it to snap in two without too much stress, and it hardly even splinters due to the short grain. I'd choose something else that has characteristics more compatible with pine/fir.

I once tested laminations of WRC and bamboo canes. The WRC failed even under very low impacts and shocks, so I personally wouldn't even think of using it. I reckon a pane of glass can flex more under stress than WRC! Being a light timber, with one exception that I can think of, if it had any virtues for sporting equipment at all it would have been used. The exception was for table tennis bats!

But it IS your mast and hey, a little R&D can be fun

After working on the other chine on my Simmons I've concluded Simon is right about the stickiness after removing the packing tape. As I pulled the tape off I could see areas where the adhesive had been pulled off and in those areas only I found the surface of the cured epoxy was tacky. Where there was no missing adhesive the epoxy wasn't tacky.

I believe I read where Dudley Dix used a combination of WRC and poplar for the bird's mouth mast for his Paper Jet 14 prototype. It didn't sound like a real good idea to me but it seems to have survived so far.

Yes, I have decided against WRC staves and will be mixing in Sitka with my local spruce and putting the Sitka on the load bearing axes which should be an awesome mast.

I saw Dudley's birdsmouth spars at the Wooden Boat show. Extremely light and cheap, using Home Depot cedar and poplar. He thinks out of the box.

There is no interaction between packaging tape adhesive an epoxy, though cured epoxy may retain some of the tape's adhesive when removed. It sands off.

Dudley Dix used the two different species when building the prototype for Paper Jet, because it was what was available and he was rushing to finish. Given a choice he wouldn't have mixed the two and he's worried about the mixture ever since.

Lowe's and Home Depot carry a type of 2x4 called an "economy stud". It comes in 93.375" lengths (not 96") and in most of the country it's white spruce. Look at it carefully, checking it's color against the regular 2x4's and 2x8's, which will have more yellow in them. If you notice they are especially pale almost white and much lighter weight compared to a regular yellow 2x4, then buy a bunch of them. You'll cut around the defects and splice staves together, but it's very light wood, good compresive and elongation strength for it's weight and cheap.

PAR, I remember you recommending the economy studs. I checked at HD a couple of times when I was looking for wood for my mast. The economy studs I found had a lot of knots and the grain was not very tight. I think I could have found enough good wood to make the mast by sorting through the whole pile and making many scarfs but then I looked over at the douglas fir boards and they are absolutely clear and tight grained. They also ranged in weight almost 2:1 in the same size (yes I weighed a bunch of them so I selected the lighter boards. All of the finished staves for my mast weighed ~19 lbs before epoxying etc. I'm guessing the finished mast will be around 22lb. How much lighter do you think a spruce mast could be?

Less then 14 pounds, possibly less then 12, before epoxy for the spruce, which is substantial and yes the pickings can be poor. I regularly go through skid after skid of this stuff often coming away with just a handful of 2x4's.

I can't believe a month has flown by!

Finally got to rounding the mast. Not too hard but a fair bit of sanding labor. I planed the mast to an octagon and then to a sixteenagon. I should have planed a bit more to ease the sanding. The mast started out very straight but has warped a bit (maybe 1/4") after all the sanding. This has coincided with our summer heat and humidity finally dropping so that may be the cause, rather than the sanding.



I made a semicircular sanding block by laying up some scrap fiberglass over a 3" PVC pipe. The 3" pipe was a bit under-size so I wrapped a few sheets of paper around it before laying the glass. The handle is a cutoff from the dagger board tip.





It's almost there



Some more details on my blog as always.

What Simon, you haven't got a lathe bed that long?

That's a huge amount of sanding but an awesome result.

Sadly it's a bit late now (aint that always the way) but you'd be amazed at how close to round you can get something using a plane and a spokeshave. At least you resisted the urge to sand around the mast (cross grain) like a lot of people suggest - yes, it's efficient if you're after round but man does it leave some deap scratches that take more sanding out than if you'd only sanded with the grain in the first place.

You've done well mate. Don't be fussed about perfectly round because you'll find that you learn to love the little imperfections that say that this mast was made by hand

Richard

What Simon, you haven't got a lathe bed that long?

Believe me, I thought about rigging up some monster contraption with belts and pulleys but what little shred of sanity I have left prevailed.

Daddles - Yeah, I definitely could have planed more. But I'm still scared of going too far with it and creating a flat that then would take a huge amount further planing / sanding to remove. No doubt my next mast will take half as long to build.

I like the tool you made!!! Duckflat buy sheets of velcro that fibre backed sandpaper will stick to.

They then glue pieces of it to all different shaped backing blocks.

MIK

I've seen commercial sanding blocks made that way but did not realize you could buy sheets of the velcro material, that's good to know.

If you spray a light coat of spray mount like 3M77 on both surfaces and let it dry for a few minutes the bond, while plenty secure for sanding, is weak enough to allow the paper to be peeled off and replaced. Just don't use a lot of the glue, a light mist coat is plenty.

Cool tool, Simon. I like shaped blocks like that. I am a bit of a collector of blocks of different sizes, shapes, etc.

On oars and spars, I shave with a plane and a spokeshave as round as I can go using a trick using chalk and paper to mark high spots and then use a roll of stick it sand paper and wrap it around the spar/oar and sand that way. Amazingly quick. The problem with shaped blocks, esp. rigid ones, is that the diameter changes along the spar.

A 1/4" off isn't too bad but I know how you feel, after all that work to glue it up straight.

Cheers,
Clint

I'm back at it and hope to churn and burn to get this Goat afloat!

Started epoxy coating the mast and was unable to do wet on wet as it's just too cold here in FL (?? #$%#$ ??) for the epoxy to set quickly enough. Otherwise no problems, will just do a light sanding between coats. I'm using MAS so no worries about blushing. In hindsight I should have done a nicer job of fitting the base plug as it is visible when the mast is unstepped. I'm planning on wrapping a bit of fiberglass tape around the base and at the partners for chafe protection.



I have also cut out all of the major plywood parts other than the bottom. The Joubert Okoume is really nice looking stuff and well worth the extra money over the Chinese Okoume I initially got. Although if you were to paint the entire boat I think the China stuff would work just fine, it's just not nearly as pretty.



A couple more pics are on my blog.