Re: Gypsy mast
--- In bolger@y..., "prthober" <prthober@p...> wrote:
rather than the specified 2 1/2. Common sense
reckon you could have 2 pieces running the full lenght and
2 "cheeks" laminated on at the bottom cut from the off cuts.
I suspect this would be a bulletproof mast.
Our Junebug mast is a single tapered piece of 100 yearold Douglas
Fir 2" squareand works just fine. Dont forget its supposed to Bend.
Cheers Paul
> Good wood for masts is hard to find. I looked at some Douglas Fir1X4
> flooring that is quarter sawn, straight and clear. Three pieceswould
> make the mast 2 1/4Are they 3/4 or 1"?
rather than the specified 2 1/2. Common sense
> tells me that this should be strong enough considering the qualityof
> the wood. Thoughts?If you did an cross section drawing and drew in your thicknesses I
>
> Paul
reckon you could have 2 pieces running the full lenght and
2 "cheeks" laminated on at the bottom cut from the off cuts.
I suspect this would be a bulletproof mast.
Our Junebug mast is a single tapered piece of 100 yearold Douglas
Fir 2" squareand works just fine. Dont forget its supposed to Bend.
Cheers Paul
--- In bolger@y..., "prthober" <prthober@p...> wrote:
rather than the specified 2 1/2. Common sense
reckon you could have 2 pieces running the full lenght and
2 "cheeks" laminated on at the bottom cut from the off cuts.
I suspect this would be a bulletproof mast.
Our Junebug mast is a single tapered piece of 100 yearold Douglas
Fir 2" squareand works just fine. Dont forget its supposed to Bend.
Cheers Paul
> Good wood for masts is hard to find. I looked at some Douglas Fir1X4
> flooring that is quarter sawn, straight and clear. Three pieceswould
> make the mast 2 1/4Are they 3/4 or 1"?
rather than the specified 2 1/2. Common sense
> tells me that this should be strong enough considering the qualityof
> the wood. Thoughts?If you did an cross section drawing and drew in your thicknesses I
>
> Paul
reckon you could have 2 pieces running the full lenght and
2 "cheeks" laminated on at the bottom cut from the off cuts.
I suspect this would be a bulletproof mast.
Our Junebug mast is a single tapered piece of 100 yearold Douglas
Fir 2" squareand works just fine. Dont forget its supposed to Bend.
Cheers Paul
I just checked my Brick plans. Brick is probably far more stable (it's
almost 4 feet wide at waterline for entire length of waterline), has a
mast almost as long, and uses the same sail. Brick mast is 2 1/4. You
are probably safe.
almost 4 feet wide at waterline for entire length of waterline), has a
mast almost as long, and uses the same sail. Brick mast is 2 1/4. You
are probably safe.
--- In bolger@y..., "rnlocnil" <lincolnr@m...> wrote:
snip
> --- In bolger@y..., "Harry W. James" <welshman@p...> wrote:
> > I would think it is OK, snip
> > prthober wrote:
> > >
> > > Good wood for masts is hard to find. I looked at some Douglas
Fir
> 1X4
> > > flooring that is quarter sawn, straight and clear. Three pieces
> would
> > > make the mast 2 1/4 rather than the specified 2 1/2. Common
sense
> > > tells me that this should be strong enough considering the
quality
> of
> > > the wood. Thoughts?
> > >
> > >
Beware of common sense. You MIGHT get away with it. If you want the
mast to behave the same as designed, you will need wood which is about
50% stiffer and 37% stronger than what was assumed in the design. I
would guess that it will be adequately strong but noticeably more
flexible. We have a similar mast for our Brick and it does
flex noticably (which can be a good thing up to a point). Couldn't you
just add a little more wood near the base before you cut the taper?
You wouldn't need to add a whole lot. If you cut the taper one way in
the boards before gluing them up, I'll bet you'd have pieces big
enough to do do the job left over.
Per the equation from an earlier post (if you remove the numbers for
the ID and straighten out the algebra), stiffness of a solid, round
mast will go with the fourth power of the diameter and strength will
go with third power. Or else my brain is turning to mush.
mast to behave the same as designed, you will need wood which is about
50% stiffer and 37% stronger than what was assumed in the design. I
would guess that it will be adequately strong but noticeably more
flexible. We have a similar mast for our Brick and it does
flex noticably (which can be a good thing up to a point). Couldn't you
just add a little more wood near the base before you cut the taper?
You wouldn't need to add a whole lot. If you cut the taper one way in
the boards before gluing them up, I'll bet you'd have pieces big
enough to do do the job left over.
Per the equation from an earlier post (if you remove the numbers for
the ID and straighten out the algebra), stiffness of a solid, round
mast will go with the fourth power of the diameter and strength will
go with third power. Or else my brain is turning to mush.
--- In bolger@y..., "Harry W. James" <welshman@p...> wrote:
> I would think it is OK, snip
> prthober wrote:
> >
> > Good wood for masts is hard to find. I looked at some Douglas Fir
1X4
> > flooring that is quarter sawn, straight and clear. Three pieces
would
> > make the mast 2 1/4 rather than the specified 2 1/2. Common sense
> > tells me that this should be strong enough considering the quality
of
> > the wood. Thoughts?
> >
> >
I would think it is OK, especially as you have a three layer lamination
of a pretty strong wood. Are you sure it is Douglas Fir not Hemlock? A
local lumber mill has gotten a hardwood rating for Hemlock for flooring,
great looking stuff, it is supposed to be not as strong and more brittle
than Doug Fir. Second growth hemlock is often sold for framing and my
English language abilities fail in the quest to impugn it properly.
HJ
prthober wrote:
of a pretty strong wood. Are you sure it is Douglas Fir not Hemlock? A
local lumber mill has gotten a hardwood rating for Hemlock for flooring,
great looking stuff, it is supposed to be not as strong and more brittle
than Doug Fir. Second growth hemlock is often sold for framing and my
English language abilities fail in the quest to impugn it properly.
HJ
prthober wrote:
>
> Good wood for masts is hard to find. I looked at some Douglas Fir 1X4
> flooring that is quarter sawn, straight and clear. Three pieces would
> make the mast 2 1/4 rather than the specified 2 1/2. Common sense
> tells me that this should be strong enough considering the quality of
> the wood. Thoughts?
>
>
Good wood for masts is hard to find. I looked at some Douglas Fir 1X4
flooring that is quarter sawn, straight and clear. Three pieces would
make the mast 2 1/4 rather than the specified 2 1/2. Common sense
tells me that this should be strong enough considering the quality of
the wood. Thoughts?
Paul
flooring that is quarter sawn, straight and clear. Three pieces would
make the mast 2 1/4 rather than the specified 2 1/2. Common sense
tells me that this should be strong enough considering the quality of
the wood. Thoughts?
Paul