Speaking of tapers, bevels and chamfering the ideal mechanical taper for a
pressure fit is 7 degrees. Speaking of degrees, (for those of us on this
side of the pond) to change Centigrade to Farenheit mutliply by 1.8 and add
32. To minimize warpage of a plank rip it into several narrow planks and
flip every other one before gluing. Teak is hard to glue. wipe it with
acetone to remove the oil before gluing. After it dries wipe it with acetone
again. It should be doweled or joined with plates or biscuits before gluing.
To make a poor mans plate joint cut a slot down the length of each plank.
The standard width of a cut (or kerf) from a regular table saw blade is 1/8"
(on this side of the pond). Cut the slot 1/2" deep. Cut a piece of oak so
its 1/8" by 1" by however long the joint is to be. Sand it heavily with a
coarse grit sandpaper. You want it to fit easily in the slot. Add some 406
thickener to some epoxy and and coat the oak and the slots with it. Join
them, wipe the excess off with acetone and clamp. If you want it really
strong use a doweling jig. Clamp the jig to the plank and drill a 3/16" hole
through it and the subsequent planks. Use care to align the holes in each
plank. When you have them all drillled use threaded 3/16 " brass or
stainless rod to hold them together.
Never screw a piano hinge into the edge of plywood. To make plywood cockpit
covers and use a piano hinge do a scarf joint first. To join plywood you
need a 7:1 angle. Example is for 1/2" plywood draw a line 3 1/2" from the
edge and taper from that line to a knife edge on the end of the sheet. Two
sheets can be glued together that way. Instead of using a second sheet of
plywood do the same angle in a piece of oak or other hardwood. Glue the two
pieces together and you can then screw the piano hinge into the edge of the
oak. Now if you want to make this really stong you can use a variation of
'the stitch and glue" technique. Stitch and glue is used when you are
epoxying pieces of wood together. Holes are drilled in the wood to be joined
and copper wire is passed through the holes after the pieces are glued. The
wire is twisted to hold the pieces together. After the epoxy is set the
wires are untwisted. You heat the wires to let the epoxy soften and then use
pliers to pull the wires out. The holes left are then filed with more epoxy.
My variation on this is to use fishing line to "sew" the pieces together.
Take the two pieces that you glued together with the scarf joint and use a
table saw to cut a 1/16" deep slot down the middle of the joint. Do it to
the opposite side also. Drill holes from top to bottom through the slots.
Space them about every half inch.
Use a large needle and pass a piece of fishing line through the hole at one
end. Put a needle on the other end and then sew through each hole. Right
hand needle come out of the 2nd hole on the left side and the left hand
needle comes out of the 2nd hole on the right side. Repeat this until you
reach the last hole and tie the two ends with a square knot. the knot can be
tied so that it inside the last hole. The line should be in the slots you
cut. Fill the slot on one side with thickened epoxy and let it set filled
side down. After it is set fill the hole from the other side with thin
epoxy.
Use the new fishing line thats out. It's made from spectra and is very
stong. Ever think about those very short screws holding the the latches to
the bottom of the hatchs? The latches on Lyric are sewn on instead of
screwed. If you want a teak look to the hatch thin strips can be glued to
the top. If you want this incredibly strong epoxy a layer of kevlar to the
top of the plywood.
I didn't use a 7 degree taper when I filled through hulls. I beveled at
about 6:1 and used woven roven for the first piece and held it in place form
the outside with a brace. After it started to kick I removed the brace and
used a serrated knife to cut the excess off. Hold the knife parralell to the
hull when you cut and you should be able to remove most of the excess with
out removeing the plug. This is going to leave a big dent where the patch is
so fill that with discs cut from mat. Use a thickener after you wet the
disks and place them one on top of the other. If you are still worried about
the patch falling out you could probably sew it in place.
Thats my 2 cents worth of stuff I learned by trial and error or from other
folks. Hope somebody finds it useful. To everyone at the rendevous, I envy
you! Maybe Judy and I will manage to find the time to get Lyric home later
this year and join you next year.
Walt, S/V Lyric #120
pressure fit is 7 degrees. Speaking of degrees, (for those of us on this
side of the pond) to change Centigrade to Farenheit mutliply by 1.8 and add
32. To minimize warpage of a plank rip it into several narrow planks and
flip every other one before gluing. Teak is hard to glue. wipe it with
acetone to remove the oil before gluing. After it dries wipe it with acetone
again. It should be doweled or joined with plates or biscuits before gluing.
To make a poor mans plate joint cut a slot down the length of each plank.
The standard width of a cut (or kerf) from a regular table saw blade is 1/8"
(on this side of the pond). Cut the slot 1/2" deep. Cut a piece of oak so
its 1/8" by 1" by however long the joint is to be. Sand it heavily with a
coarse grit sandpaper. You want it to fit easily in the slot. Add some 406
thickener to some epoxy and and coat the oak and the slots with it. Join
them, wipe the excess off with acetone and clamp. If you want it really
strong use a doweling jig. Clamp the jig to the plank and drill a 3/16" hole
through it and the subsequent planks. Use care to align the holes in each
plank. When you have them all drillled use threaded 3/16 " brass or
stainless rod to hold them together.
Never screw a piano hinge into the edge of plywood. To make plywood cockpit
covers and use a piano hinge do a scarf joint first. To join plywood you
need a 7:1 angle. Example is for 1/2" plywood draw a line 3 1/2" from the
edge and taper from that line to a knife edge on the end of the sheet. Two
sheets can be glued together that way. Instead of using a second sheet of
plywood do the same angle in a piece of oak or other hardwood. Glue the two
pieces together and you can then screw the piano hinge into the edge of the
oak. Now if you want to make this really stong you can use a variation of
'the stitch and glue" technique. Stitch and glue is used when you are
epoxying pieces of wood together. Holes are drilled in the wood to be joined
and copper wire is passed through the holes after the pieces are glued. The
wire is twisted to hold the pieces together. After the epoxy is set the
wires are untwisted. You heat the wires to let the epoxy soften and then use
pliers to pull the wires out. The holes left are then filed with more epoxy.
My variation on this is to use fishing line to "sew" the pieces together.
Take the two pieces that you glued together with the scarf joint and use a
table saw to cut a 1/16" deep slot down the middle of the joint. Do it to
the opposite side also. Drill holes from top to bottom through the slots.
Space them about every half inch.
Use a large needle and pass a piece of fishing line through the hole at one
end. Put a needle on the other end and then sew through each hole. Right
hand needle come out of the 2nd hole on the left side and the left hand
needle comes out of the 2nd hole on the right side. Repeat this until you
reach the last hole and tie the two ends with a square knot. the knot can be
tied so that it inside the last hole. The line should be in the slots you
cut. Fill the slot on one side with thickened epoxy and let it set filled
side down. After it is set fill the hole from the other side with thin
epoxy.
Use the new fishing line thats out. It's made from spectra and is very
stong. Ever think about those very short screws holding the the latches to
the bottom of the hatchs? The latches on Lyric are sewn on instead of
screwed. If you want a teak look to the hatch thin strips can be glued to
the top. If you want this incredibly strong epoxy a layer of kevlar to the
top of the plywood.
I didn't use a 7 degree taper when I filled through hulls. I beveled at
about 6:1 and used woven roven for the first piece and held it in place form
the outside with a brace. After it started to kick I removed the brace and
used a serrated knife to cut the excess off. Hold the knife parralell to the
hull when you cut and you should be able to remove most of the excess with
out removeing the plug. This is going to leave a big dent where the patch is
so fill that with discs cut from mat. Use a thickener after you wet the
disks and place them one on top of the other. If you are still worried about
the patch falling out you could probably sew it in place.
Thats my 2 cents worth of stuff I learned by trial and error or from other
folks. Hope somebody finds it useful. To everyone at the rendevous, I envy
you! Maybe Judy and I will manage to find the time to get Lyric home later
this year and join you next year.
Walt, S/V Lyric #120