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Making the Inner and Outer Stem Pieces
I can’t count the number of times I have steamed wood and bent them to my will but I can tell you that I
still get a kick out of seeing a hard piece of Ash bend like a soft piece of lead around a stem form after
a few minutes of steam. Typically in a large boat shop this is a big deal with a large apparatus gas
fired burners and boxes full of planks. However in your boat shop a simple piece of PVC pipe and an
electric teakettle or wallpaper steamer will do the trick. In fact, about anything that generates steam
will probably do the trick. Chances are you have what you need to get this done but if not, about $40
to $50 will take care of setting up shop.
still get a kick out of seeing a hard piece of Ash bend like a soft piece of lead around a stem form after
a few minutes of steam. Typically in a large boat shop this is a big deal with a large apparatus gas
fired burners and boxes full of planks. However in your boat shop a simple piece of PVC pipe and an
electric teakettle or wallpaper steamer will do the trick. In fact, about anything that generates steam
will probably do the trick. Chances are you have what you need to get this done but if not, about $40
to $50 will take care of setting up shop.
In the picture to the left is a simple electric teakettle with a 4-foot
piece of PVC pipe over the spout with a cap on the end. A 3-inch
pipe will handle 4 to 6 strips at a time. However If this is your first
time bending wood you may want to work with just a couple of
strips at a time. For ¼” strips of hardwood you will want to stem
for about 20 minutes. You really can’t over steam wood but you
can under steam them.
When pulling the strips from the steamer, be sure and have
gloves ready to work with. Steam is very hot, ergo; the wood in
the steamer is also very hot. When you pull the strips from the
pipe, you will have about 60 seconds or so of prime working
time. If the wood has steamed enough, the strips will bend
around the stem with no effort at all.
Start by putting the strips all the way to the end of the stem piece
and clamp them down. Not too hard, you simply need to hold
them in place while they dry. Once you have the strips pinned
down to the stem form, go to about the half way mark down the
stem form and put another clamp in and wasting no time work
your way to the end of the form and put another clamp to finish
the bend. You should be able to accomplish all of this in the first
60 seconds after pulling the strips out of the steamer.
Probably the most useful tip I can give you for this process is to
make sure that all of your clamps are at hand and open
reasonably close to the thickness of what you are clamping.
You should be able to clamp with just a couple of turns of the
screw.
The most important advice that I can give you is to know when to
admit defeat. It doesn’t happen very often, but occasionally a
piece will crack. This, for me has always happened for one of
two reasons. First, I got impatient and pulled them from the
steamer before they were sufficiently cooked (definitely my fault),
and second, the grain of the wood was in a bad way in a bad
place. From time to time a wide piece of grain will end up right at
the middle of the bend. This is just a bad piece of luck.
piece of PVC pipe over the spout with a cap on the end. A 3-inch
pipe will handle 4 to 6 strips at a time. However If this is your first
time bending wood you may want to work with just a couple of
strips at a time. For ¼” strips of hardwood you will want to stem
for about 20 minutes. You really can’t over steam wood but you
can under steam them.
When pulling the strips from the steamer, be sure and have
gloves ready to work with. Steam is very hot, ergo; the wood in
the steamer is also very hot. When you pull the strips from the
pipe, you will have about 60 seconds or so of prime working
time. If the wood has steamed enough, the strips will bend
around the stem with no effort at all.
Start by putting the strips all the way to the end of the stem piece
and clamp them down. Not too hard, you simply need to hold
them in place while they dry. Once you have the strips pinned
down to the stem form, go to about the half way mark down the
stem form and put another clamp in and wasting no time work
your way to the end of the form and put another clamp to finish
the bend. You should be able to accomplish all of this in the first
60 seconds after pulling the strips out of the steamer.
Probably the most useful tip I can give you for this process is to
make sure that all of your clamps are at hand and open
reasonably close to the thickness of what you are clamping.
You should be able to clamp with just a couple of turns of the
screw.
The most important advice that I can give you is to know when to
admit defeat. It doesn’t happen very often, but occasionally a
piece will crack. This, for me has always happened for one of
two reasons. First, I got impatient and pulled them from the
steamer before they were sufficiently cooked (definitely my fault),
and second, the grain of the wood was in a bad way in a bad
place. From time to time a wide piece of grain will end up right at
the middle of the bend. This is just a bad piece of luck.
The inner and outer stem is the natural evolution to this process making what was once a one-piece
stem into a two-piece stem. The inner stem is either a laminated or sawn piece of wood (in our case
the former), which accepts the strips. After the stripping process, the outer stem is added, rounded
over or shaped and you are done. This split stem is just as strong, possibly stronger than the
traditional stem piece and in most cases, far easier and quicker to accomplish.
stem into a two-piece stem. The inner stem is either a laminated or sawn piece of wood (in our case
the former), which accepts the strips. After the stripping process, the outer stem is added, rounded
over or shaped and you are done. This split stem is just as strong, possibly stronger than the
traditional stem piece and in most cases, far easier and quicker to accomplish.
After the inner and outer stem pieces have been clamped, give them a good 24 hours to set. The
process of steaming the wood significantly raises the moisture level and before we go on to the
next step of gluing them up we need to let that moisture work its way out. The longer you leave
them clamped to the stem, the better they will take the shape of the stem and this will make glue up
much easier. Glue up is where the actual process of making a laminated stem takes place.
Remember as you go through this entire process that it is effectively the same for a 20 foot
runabout. The only difference is the actual size of the stem you are laminating.
process of steaming the wood significantly raises the moisture level and before we go on to the
next step of gluing them up we need to let that moisture work its way out. The longer you leave
them clamped to the stem, the better they will take the shape of the stem and this will make glue up
much easier. Glue up is where the actual process of making a laminated stem takes place.
Remember as you go through this entire process that it is effectively the same for a 20 foot
runabout. The only difference is the actual size of the stem you are laminating.
The glue up is not a particularly tricky thing to do; in fact it is
straightforward. What is important here is cleanliness. Getting
sloppy here may wind up producing one large stem as opposed
to an inner and outer stem. From the picture you can see that
although the inner and outer stem are glued up at the same time,
they are separated by painters tape. You may be temped to
laminate the inner and outer stem separately, however I have
found that laminating them together results in a better final fit.
When you glue them up they will hold the final shape of the stem
and by laminating them together the outer stem will fit right over
the inner stem like a puzzle piece when the time comes. You can
use a number of different kinds of glues to laminate the stems,
clear glue, or one that does not stain the wood. I prefer to use a
mixture of slow hardening epoxy with wood flour. The slow
hardener allows for a good penetration to the hardwood. The
process is easy, remove all the strips from the form. Put a piece
of painters tape along the edge of the form and replace the first
strip. Using an acid brush, generously coat the top of the first
strip and the underside of the second strip. Place a piece of
painters tape on top of the second strip. Lay the third strip on top
of the painters tape and again, coat the top of the third strip and
the underside of the fourth. You should be using gloves during
this process if you are working with epoxy. Now take some time
to align the strips side to side and re-clamp them together being
careful not to over tighten. When using epoxy, you do not need to
over clamp, and in fact squeezing out all of the epoxy is not a
good thing. You want to spend a as much time as necessary to
make sure that the strips line up well so that when they are taken
apart you don’t need to shape them other than a light sanding.
same. Make sure you take the time to carefully wipe off all the wet
epoxy before it sets. It is easier to wipe off now then it is to sand
simply peal the stem pieces off of the stem form. Now that you to
good use.have your stem forms back you can move on to the
next task of setting up the forms on the strongback and put those
stem pieces to good use.
straightforward. What is important here is cleanliness. Getting
sloppy here may wind up producing one large stem as opposed
to an inner and outer stem. From the picture you can see that
although the inner and outer stem are glued up at the same time,
they are separated by painters tape. You may be temped to
laminate the inner and outer stem separately, however I have
found that laminating them together results in a better final fit.
When you glue them up they will hold the final shape of the stem
and by laminating them together the outer stem will fit right over
the inner stem like a puzzle piece when the time comes. You can
use a number of different kinds of glues to laminate the stems,
clear glue, or one that does not stain the wood. I prefer to use a
mixture of slow hardening epoxy with wood flour. The slow
hardener allows for a good penetration to the hardwood. The
process is easy, remove all the strips from the form. Put a piece
of painters tape along the edge of the form and replace the first
strip. Using an acid brush, generously coat the top of the first
strip and the underside of the second strip. Place a piece of
painters tape on top of the second strip. Lay the third strip on top
of the painters tape and again, coat the top of the third strip and
the underside of the fourth. You should be using gloves during
this process if you are working with epoxy. Now take some time
to align the strips side to side and re-clamp them together being
careful not to over tighten. When using epoxy, you do not need to
over clamp, and in fact squeezing out all of the epoxy is not a
good thing. You want to spend a as much time as necessary to
make sure that the strips line up well so that when they are taken
apart you don’t need to shape them other than a light sanding.
same. Make sure you take the time to carefully wipe off all the wet
epoxy before it sets. It is easier to wipe off now then it is to sand
simply peal the stem pieces off of the stem form. Now that you to
good use.have your stem forms back you can move on to the
next task of setting up the forms on the strongback and put those
stem pieces to good use.
Years ago stem pieces were not used in canoe
building. You simply stripped up to the stem
form and interlocked the strips with each other
then carefully rounded over the ends and put a
healthy amount of fiberglass over the stem to
make sure it didn't come apart on you when you
hit that rock head on. These days, canoe
builders have taken a cue from the earlier days
of boat building where a stem piece was
employed. If you are a student of boat building,
you have undoubtedly seen stems rabbeted out
to accept planking. The inner and outer stem is
the natural evolution to this process making
what was once a one-piece stem into a two-
piece stem. A laminated Two piece stem is
strong, easy to apply and flexible with the
design. The following is a tutorial.
building. You simply stripped up to the stem
form and interlocked the strips with each other
then carefully rounded over the ends and put a
healthy amount of fiberglass over the stem to
make sure it didn't come apart on you when you
hit that rock head on. These days, canoe
builders have taken a cue from the earlier days
of boat building where a stem piece was
employed. If you are a student of boat building,
you have undoubtedly seen stems rabbeted out
to accept planking. The inner and outer stem is
the natural evolution to this process making
what was once a one-piece stem into a two-
piece stem. A laminated Two piece stem is
strong, easy to apply and flexible with the
design. The following is a tutorial.