RE: [bolger] breaking micro's chine logs
Jason, I worry that since you've already epoxied those chine logs onto the
side panels, you will indeed have a hard time bending the whole thing onto
the bulkheads - you've effectively laminated a straight beam (in the lateral
direction), and once the epoxy sets up, the structure will want to maintain
the shape that is set into it, much more than the two pieces would
separately, if they could move against one-another. The outside piece, in
this case the sheet of plywood, would effectively have to bend over a larger
radius curve than the inside piece, the chine log, and if free to do this
there would be less resistance to bending; but if they're bonded together
you essentially have a single piece now, and that will not want to bend so
easiy. I don't know if this will help or hurt your breaking issue, but I
suspect it will make the overall task more difficult, especially if you're
using 3/8" MDO.
I didn't have any trouble with my chine logs; I rooted through the pile and
chose the straightest-grained 16' board of so-called mahogany decking stock
at my local yard before the yard guys came and chased me off, and ripped
both logs from that; I did not oversize mine like Peter did, and really had
no trouble bending them to the bulkhead curves, which I had mounted in a
strongback. I had slightly more trouble bending the optional Lenihan-style
inner keelson, but managed to persuade it. I'd built 4 boats before this,
all on a strongback, had seen Peter's photos on duckworks and just
automatically went about building myself a ladder-frame strongback to start
out - only recently while reading the whole philosophical debate here on how
much of a production building a Bolger 'instant boat' should be, and
re-reading Payson's books, did it occur to me that Micro was perhaps
actually meant to be built without such a structure! I did lose alot of time
getting things aligned, I won't argue that. But if I had it to do again, I
think I'd probably still go about it the same way, for the security and
convenience it provided. It made working alone alot easier, and made my
whole project mobile by bolting casters under the strongback once the
crucially-aligned parts were permanently attached to each other.
Good luck with your boat!
Paul Lefebvre
-----Original Message-----
From: Jason Stancil [mailto:jasonstancil@...]
Sent: Thursday, April 15, 2004 9:36 PM
To:bolger@yahoogroups.com
Subject: [bolger] breaking micro's chine logs
Tommorrow i hope to make my micro 3d. Problem is i keep breaking the
lumber i cut to use as chine logs and sheer clamps. I got 7 out of
one 16 foot board. Three did'nt survive my flex test....down to 4
logs.......successfully attached the logs to the side panels but to
be honest i have no faith those panels are going to flex around the
frames/bulkheads without snapping. Any hints how not to break the
logs bending the panels? I'm hoping the plywood backing will brace
them and keep them from snapping. Now that the logs are epoxied on
i'm dreading having to grind them off if i break one during assembly.
Is the spruce/ pine / fir known to be brittle?
Thanks,
Jason
side panels, you will indeed have a hard time bending the whole thing onto
the bulkheads - you've effectively laminated a straight beam (in the lateral
direction), and once the epoxy sets up, the structure will want to maintain
the shape that is set into it, much more than the two pieces would
separately, if they could move against one-another. The outside piece, in
this case the sheet of plywood, would effectively have to bend over a larger
radius curve than the inside piece, the chine log, and if free to do this
there would be less resistance to bending; but if they're bonded together
you essentially have a single piece now, and that will not want to bend so
easiy. I don't know if this will help or hurt your breaking issue, but I
suspect it will make the overall task more difficult, especially if you're
using 3/8" MDO.
I didn't have any trouble with my chine logs; I rooted through the pile and
chose the straightest-grained 16' board of so-called mahogany decking stock
at my local yard before the yard guys came and chased me off, and ripped
both logs from that; I did not oversize mine like Peter did, and really had
no trouble bending them to the bulkhead curves, which I had mounted in a
strongback. I had slightly more trouble bending the optional Lenihan-style
inner keelson, but managed to persuade it. I'd built 4 boats before this,
all on a strongback, had seen Peter's photos on duckworks and just
automatically went about building myself a ladder-frame strongback to start
out - only recently while reading the whole philosophical debate here on how
much of a production building a Bolger 'instant boat' should be, and
re-reading Payson's books, did it occur to me that Micro was perhaps
actually meant to be built without such a structure! I did lose alot of time
getting things aligned, I won't argue that. But if I had it to do again, I
think I'd probably still go about it the same way, for the security and
convenience it provided. It made working alone alot easier, and made my
whole project mobile by bolting casters under the strongback once the
crucially-aligned parts were permanently attached to each other.
Good luck with your boat!
Paul Lefebvre
-----Original Message-----
From: Jason Stancil [mailto:jasonstancil@...]
Sent: Thursday, April 15, 2004 9:36 PM
To:bolger@yahoogroups.com
Subject: [bolger] breaking micro's chine logs
Tommorrow i hope to make my micro 3d. Problem is i keep breaking the
lumber i cut to use as chine logs and sheer clamps. I got 7 out of
one 16 foot board. Three did'nt survive my flex test....down to 4
logs.......successfully attached the logs to the side panels but to
be honest i have no faith those panels are going to flex around the
frames/bulkheads without snapping. Any hints how not to break the
logs bending the panels? I'm hoping the plywood backing will brace
them and keep them from snapping. Now that the logs are epoxied on
i'm dreading having to grind them off if i break one during assembly.
Is the spruce/ pine / fir known to be brittle?
Thanks,
Jason
I don't know if it applies here, but I read an article on bending wood that
emphasized that the wood must be kept in compression to avoid breaking.
Push it into the forms. It even showed a fixture which applied a steel band
to the outside of the wood with stops on the ends so that the outside fibers
wouldn't be stretched, but that's probably more applicable to production
work.
Roger
derbyrm@...
http://derbyrm.mystarband.net
emphasized that the wood must be kept in compression to avoid breaking.
Push it into the forms. It even showed a fixture which applied a steel band
to the outside of the wood with stops on the ends so that the outside fibers
wouldn't be stretched, but that's probably more applicable to production
work.
Roger
derbyrm@...
http://derbyrm.mystarband.net
----- Original Message -----
From: "Bruce Hallman" <bruce@...>
> --- Jason Stancil wrote:
> > i keep breaking the
> > lumber i cut to use
> > as chine logs and sheer clamps.
>
> I recall you mentioned that
> you were thinking of making
> them 1" instead of the 3/4"
> shown on the plans? 3/4"
> would bend better than 1".
--- Jason Stancil wrote:
you were thinking of making
them 1" instead of the 3/4"
shown on the plans? 3/4"
would bend better than 1".
> i keep breaking theI recall you mentioned that
> lumber i cut to use
> as chine logs and sheer clamps.
you were thinking of making
them 1" instead of the 3/4"
shown on the plans? 3/4"
would bend better than 1".
--- Inbolger@yahoogroups.com, "Jason Stancil" <jasonstancil@h...>
wrote:
Just about any wood can be made to bend without breaking.It all
depends on how patient you can be.Since I had slightly increased the
scantlings on my Micros chine logs,I just"knew" they would not take
the compound curve easily,so I soaked them with a towel drenched in
hot water and left them over-night with a weight attached to the
ends.By morning,the job was done and the mahogany went in without so
much as a snap.
You are using a strong back,aren't you? And all the notches are
cut to recieve the chine logs? Secure one of your chine logs to
either the transom or the bow transom and then tie a weight to the
other end while using ropes to encourage them to bend in the
horizontal plane.Use a towel,soaked with hot water,at the point of
greatest curvature(main bulkhead).
If you have already epoxied the chine logs to the side panels
BEFORE the side panels were installed ....well....it may or may not
work since you will have created something of a laminated structure
which is going to resist bending.How do you feel about using right
angle grinders and making lots of dust? :-)
You are still at a critical stage and should take pains to get
things right,even if it means waiting a day(or two?) for the chines
to bend.Once the basic hull is all done you'll have lots of non-
critical areas to enjoy and experiment with while not compromizing
hull integrity.
I think that Duckworks CD ,which Nels refered to some time
ago,has a picture essay on building a Micro hull....may be worth a
peek :-)
Good luck with your Micro.
Sincerely,
Peter Lenihan,ex builder/owner of LESTAT
wrote:
> Tommorrow i hope to make my micro 3d. Problem is i keep breakingthe
> lumber i cut to use as chine logs and sheer clamps. I got 7 out ofto
> one 16 foot board. Three did'nt survive my flex test....down to 4
> logs.......successfully attached the logs to the side panels but
> be honest i have no faith those panels are going to flex aroundthe
> frames/bulkheads without snapping. Any hints how not to break theassembly.
> logs bending the panels? I'm hoping the plywood backing will brace
> them and keep them from snapping. Now that the logs are epoxied on
> i'm dreading having to grind them off if i break one during
> Is the spruce/ pine / fir known to be brittle?Jason,
>
> Thanks,
> Jason
Just about any wood can be made to bend without breaking.It all
depends on how patient you can be.Since I had slightly increased the
scantlings on my Micros chine logs,I just"knew" they would not take
the compound curve easily,so I soaked them with a towel drenched in
hot water and left them over-night with a weight attached to the
ends.By morning,the job was done and the mahogany went in without so
much as a snap.
You are using a strong back,aren't you? And all the notches are
cut to recieve the chine logs? Secure one of your chine logs to
either the transom or the bow transom and then tie a weight to the
other end while using ropes to encourage them to bend in the
horizontal plane.Use a towel,soaked with hot water,at the point of
greatest curvature(main bulkhead).
If you have already epoxied the chine logs to the side panels
BEFORE the side panels were installed ....well....it may or may not
work since you will have created something of a laminated structure
which is going to resist bending.How do you feel about using right
angle grinders and making lots of dust? :-)
You are still at a critical stage and should take pains to get
things right,even if it means waiting a day(or two?) for the chines
to bend.Once the basic hull is all done you'll have lots of non-
critical areas to enjoy and experiment with while not compromizing
hull integrity.
I think that Duckworks CD ,which Nels refered to some time
ago,has a picture essay on building a Micro hull....may be worth a
peek :-)
Good luck with your Micro.
Sincerely,
Peter Lenihan,ex builder/owner of LESTAT
--- Inbolger@yahoogroups.com, "Jason Stancil" <jasonstancil@h...>
wrote:
You can soak the portion of the chine logs and sheer clamps where the
maximum curvature occurs with hot towels until they get more
flexible. Or you can saw relief kerfs crossways partway through on
the inner edges and fill them with slow cure epoxy, just prior to
installation.
If you recall the post about the strongback, it was recommended to
install the clamps and logs prior to installing the plywood. That way
you can either laminate them or pre-soak them.
Good Luck, Nels
wrote:
> Is the spruce/ pine / fir known to be brittle?Hi Jason,
>
> Thanks,
> Jason
You can soak the portion of the chine logs and sheer clamps where the
maximum curvature occurs with hot towels until they get more
flexible. Or you can saw relief kerfs crossways partway through on
the inner edges and fill them with slow cure epoxy, just prior to
installation.
If you recall the post about the strongback, it was recommended to
install the clamps and logs prior to installing the plywood. That way
you can either laminate them or pre-soak them.
Good Luck, Nels
Tommorrow i hope to make my micro 3d. Problem is i keep breaking the
lumber i cut to use as chine logs and sheer clamps. I got 7 out of
one 16 foot board. Three did'nt survive my flex test....down to 4
logs.......successfully attached the logs to the side panels but to
be honest i have no faith those panels are going to flex around the
frames/bulkheads without snapping. Any hints how not to break the
logs bending the panels? I'm hoping the plywood backing will brace
them and keep them from snapping. Now that the logs are epoxied on
i'm dreading having to grind them off if i break one during assembly.
Is the spruce/ pine / fir known to be brittle?
Thanks,
Jason
lumber i cut to use as chine logs and sheer clamps. I got 7 out of
one 16 foot board. Three did'nt survive my flex test....down to 4
logs.......successfully attached the logs to the side panels but to
be honest i have no faith those panels are going to flex around the
frames/bulkheads without snapping. Any hints how not to break the
logs bending the panels? I'm hoping the plywood backing will brace
them and keep them from snapping. Now that the logs are epoxied on
i'm dreading having to grind them off if i break one during assembly.
Is the spruce/ pine / fir known to be brittle?
Thanks,
Jason