Bob Cleek

If you have a table saw, minirature or otherwise, a taper jig is easy to make  from scrap lumber.  With this you can cut tapers easily and quickly. If you don’t want to make and use a marking gage the mark 1 eyeball works well to plane an octagon.  Once you have a tapered octagon, the rest is easy.
 
There are also spars that taper in a curve instead of a straight line.  Here again it is easier to first cut a straight taper and then add the curvature.  A disc sander could be used for this.
 
In building anything it’s easier to work with straight lines than curves.  While it might seem easier to make a round spar from a round dowel, it is easier to cut the basic shape from a rectangular piece of wood before shaping  the circular cross section.
 
Roger

Indeed, that's true. If you've got the right dowel and have learned to do it with a sanding block while spinning the dowel, that's often the fastest way to get the job done. 

Indeed, that's true. If you've got the right dowel and have learned to do it with a sanding block while spinning the dowel, that's often the fastest way to get the job done. 

It's sure not very well known, but that doesn't mean it's not good for modeling. Backyard ornamentals can produce some great modeling wood, too small for commercial purposes, but still great for small stuff. 
 
It's basically a climbing fig and part of the large ficus family. It's not in the wood database online.  This may be of some interest::
 
https://uses.plantnet-project.org/en/Ficus_(PROSEA_Timbers)

Those rubber donut and springed sheet horses are quite common on larger top-end yachts of the "Golden Age," but I never really understood the point of them. I've never come across anything on them in the literature. Maybe they were a fad and wealthy owners commissioning their yachts came to expect them, so the architects satisfied their expectations. They are unquestionably impressive, but the springs I've seen have always been quite strong. You'd have a hard time compressing one by hand, and the rubber donuts were hard, like tire rubber, and no more "compressible" than the springs. (After a few decades in the weather, the old rubber was hard as a rock, too!) Maybe they served to remind helmsmen that in boats of that size an uncontrolled jibe was to be avoided at all costs, but in the event of one, those shock absorbers wouldn't have made much difference. Generally, the stretch in the sheets and the flexibility of the spars provide all the "shock absorbing" that's needed in regular operation. (The stresses aren't sharp shocks, like when tires hit potholes, but rather fluctuations in tension.) On the other hand, they may have been developed to compensate for the lack of stretch in more modern construction when wire cable standing rigging and better cordage with less stretch came into use (and certainly later, when synthetic cordage came along.) I do recall an old timer from the "Big Boat" ocean racing fraternity telling me how a lot of the large ocean racers suffered a lot of busted gear, broken frames, deck leaks, and such when everybody went to Dacron line and sailcloth and hydraulic backstay tensioners and big geared deck winches to squeeze a bit more speed out of their boats. They were then able to really crank down on the rigging far beyond what the boats had ever been engineered to handle. Those "buffered" sheet horses may have been some attempt to compensate for some of that. I don't know, but they are certainly an interesting and impressive fitting.

And a tiny one at that!

Well, you're doing it the hard way. Doweling is readily available, but often it's not of a suitable wood species. Also, dowels are often not perfectly straight, nor inclined to stay that way. That's not a big problem for short lengths for pegs and such, but for a long spar, not so much.
 
What you need is a spar gauge. You can then take any size square piece of straight grained wood without any grain runout and taper it on all four sides on your table saw, or with a plane, and then use the gauge to mark the lines to plane to yield a perfectly octagonal tapered stick. After that, sanding it round is a cinch. The only catch is that it's a lot easier on a full-size spar than on a scale-size one because of the dimensions, but a modeler shouldn't have too much problem making a miniature spar gauge to suit the task. full size spar gauges use pencils to mark the lines on tapered spar stock. A modeler's spar gauge does better with sharpened nails which scribe the lines instead of penciling them on.  This web page tells you everything you need to know about making perfectly tapered round spars using a plane and sandpaper: https://www.pettigrews.org.uk/lm/page030a.htm
 

Well, you're doing it the hard way. Doweling is readily available, but often it's not of a suitable wood species. Also, dowels are often not perfectly straight, nor inclined to stay that way. That's not a big problem for short lengths for pegs and such, but for a long spar, not so much.
 
What you need is a spar gauge. You can then take any size square piece of straight grained wood without any grain runout and taper it on all four sides on your table saw, or with a plane, and then use the gauge to mark the lines to plane to yield a perfectly octagonal tapered stick. After that, sanding it round is a cinch. The only catch is that it's a lot easier on a full-size spar than on a scale-size one because of the dimensions, but a modeler shouldn't have too much problem making a miniature spar gauge to suit the task. full size spar gauges use pencils to mark the lines on tapered spar stock. A modeler's spar gauge does better with sharpened nails which scribe the lines instead of penciling them on.  This web page tells you everything you need to know about making perfectly tapered round spars using a plane and sandpaper: https://www.pettigrews.org.uk/lm/page030a.htm
 

Well, you're doing it the hard way. Doweling is readily available, but often it's not of a suitable wood species. Also, dowels are often not perfectly straight, nor inclined to stay that way. That's not a big problem for short lengths for pegs and such, but for a long spar, not so much.
 
What you need is a spar gauge. You can then take any size square piece of straight grained wood without any grain runout and taper it on all four sides on your table saw, or with a plane, and then use the gauge to mark the lines to plane to yield a perfectly octagonal tapered stick. After that, sanding it round is a cinch. The only catch is that it's a lot easier on a full-size spar than on a scale-size one because of the dimensions, but a modeler shouldn't have too much problem making a miniature spar gauge to suit the task. full size spar gauges use pencils to mark the lines on tapered spar stock. A modeler's spar gauge does better with sharpened nails which scribe the lines instead of penciling them on.  This web page tells you everything you need to know about making perfectly tapered round spars using a plane and sandpaper: https://www.pettigrews.org.uk/lm/page030a.htm
 

I can't imagine why anyone would want to try to use a "power chisel" to shape a mast. The easiest way to shape a spar is to use a plane to turn the piece into an octogon and then chuck it in a drill press or hand drill motor held in a vise and sand the dowel while it's spinning. A lathe is another obvious option, but, considering the tooling costs for taper attachment and steady rest and the setup time, planing and sanding is a lot easier. Particularly with the planing, building a "planing sled" jig for your desired taper angle will make turning out a large number of spars a piece of cake.
 
I don't do a lot of wood carving, but it seems to me that there isn't a hundred bucks worth of advantage to a vibrating chisel over a good set of well-sharpened hand carving chisels and I suspect there are a lot more blade shapes available with manual carving tool lines than with the power chisels. (It seems there only five blade shapes for the Micro-Mark model.)
 
If i had a hundred bucks to spend on a tool for shaping spars, I'd go first cabin and spend $85 on a Lie-Nielsen Model Maker's Block Plane, a high-quality recreation of the old Stanley No. 100 squirel-tailed model maker's plane and the rest on a sleeve or two of sandpaper.
 
https://www.lie-nielsen.com/products/Model Maker's Block Plane
 

Well, you're doing it the hard way. Doweling is readily available, but often it's not of a suitable wood species. Also, dowels are often not perfectly straight, nor inclined to stay that way. That's not a big problem for short lengths for pegs and such, but for a long spar, not so much.
 
What you need is a spar gauge. You can then take any size square piece of straight grained wood without any grain runout and taper it on all four sides on your table saw, or with a plane, and then use the gauge to mark the lines to plane to yield a perfectly octagonal tapered stick. After that, sanding it round is a cinch. The only catch is that it's a lot easier on a full-size spar than on a scale-size one because of the dimensions, but a modeler shouldn't have too much problem making a miniature spar gauge to suit the task. full size spar gauges use pencils to mark the lines on tapered spar stock. A modeler's spar gauge does better with sharpened nails which scribe the lines instead of penciling them on.  This web page tells you everything you need to know about making perfectly tapered round spars using a plane and sandpaper: https://www.pettigrews.org.uk/lm/page030a.htm
 

I use a small finger plane to take it down in an octagon shape and then sand...   works a treat and is quite fast. 

This my home made wood lathe. 
 

 
The plate contains a roller blade bearing and there is a ledge on the back so I can clamp it to the table.  The id of this is about 10 mm . for narrower spars I insert a wooden "washer".  I have two of these boards and for long masts I place one in the center to add more support.

I can't imagine why anyone would want to try to use a "power chisel" to shape a mast. The easiest way to shape a spar is to use a plane to turn the piece into an octogon and then chuck it in a drill press or hand drill motor held in a vise and sand the dowel while it's spinning. A lathe is another obvious option, but, considering the tooling costs for taper attachment and steady rest and the setup time, planing and sanding is a lot easier. Particularly with the planing, building a "planing sled" jig for your desired taper angle will make turning out a large number of spars a piece of cake.
 
I don't do a lot of wood carving, but it seems to me that there isn't a hundred bucks worth of advantage to a vibrating chisel over a good set of well-sharpened hand carving chisels and I suspect there are a lot more blade shapes available with manual carving tool lines than with the power chisels. (It seems there only five blade shapes for the Micro-Mark model.)
 
If i had a hundred bucks to spend on a tool for shaping spars, I'd go first cabin and spend $85 on a Lie-Nielsen Model Maker's Block Plane, a high-quality recreation of the old Stanley No. 100 squirel-tailed model maker's plane and the rest on a sleeve or two of sandpaper.
 
https://www.lie-nielsen.com/products/Model Maker's Block Plane
 

Bob; I totally agree. I purchased this plane a few years ago and LOVE IT! I made one adjustment and called lie-Nielsen before making it. The throat is not adjustable (I assume because it’s a small tool) and shavings were clogging the plane (probably my fault). I was able to file the throat area enlarging the opening by about .3mm. No more clogging. It’s a great pleasure to use...Moab

I can't imagine why anyone would want to try to use a "power chisel" to shape a mast. The easiest way to shape a spar is to use a plane to turn the piece into an octogon and then chuck it in a drill press or hand drill motor held in a vise and sand the dowel while it's spinning. A lathe is another obvious option, but, considering the tooling costs for taper attachment and steady rest and the setup time, planing and sanding is a lot easier. Particularly with the planing, building a "planing sled" jig for your desired taper angle will make turning out a large number of spars a piece of cake.
 
I don't do a lot of wood carving, but it seems to me that there isn't a hundred bucks worth of advantage to a vibrating chisel over a good set of well-sharpened hand carving chisels and I suspect there are a lot more blade shapes available with manual carving tool lines than with the power chisels. (It seems there only five blade shapes for the Micro-Mark model.)
 
If i had a hundred bucks to spend on a tool for shaping spars, I'd go first cabin and spend $85 on a Lie-Nielsen Model Maker's Block Plane, a high-quality recreation of the old Stanley No. 100 squirel-tailed model maker's plane and the rest on a sleeve or two of sandpaper.
 
https://www.lie-nielsen.com/products/Model Maker's Block Plane
 

I suggest you try this method using a hair dryer on high heat but without the water in the pan or the pan on the stove. Once the hair drier heats the wood sufficiently, I'll be it bends just as well as with the boiling water on the stove and with a lot less mess and risk of burning yourself. A hair curing iron or clothes iron applied directly to the wood are other good heat sources.

I can't imagine why anyone would want to try to use a "power chisel" to shape a mast. The easiest way to shape a spar is to use a plane to turn the piece into an octogon and then chuck it in a drill press or hand drill motor held in a vise and sand the dowel while it's spinning. A lathe is another obvious option, but, considering the tooling costs for taper attachment and steady rest and the setup time, planing and sanding is a lot easier. Particularly with the planing, building a "planing sled" jig for your desired taper angle will make turning out a large number of spars a piece of cake.
 
I don't do a lot of wood carving, but it seems to me that there isn't a hundred bucks worth of advantage to a vibrating chisel over a good set of well-sharpened hand carving chisels and I suspect there are a lot more blade shapes available with manual carving tool lines than with the power chisels. (It seems there only five blade shapes for the Micro-Mark model.)
 
If i had a hundred bucks to spend on a tool for shaping spars, I'd go first cabin and spend $85 on a Lie-Nielsen Model Maker's Block Plane, a high-quality recreation of the old Stanley No. 100 squirel-tailed model maker's plane and the rest on a sleeve or two of sandpaper.
 
https://www.lie-nielsen.com/products/Model Maker's Block Plane
 

Dry heat is all you need. There is no need, nor point to using, steam or moisture of any kind when bending wood unless you have to, and that's probably almost never when modeling. The steam or other moisture only serves the purpose of transmitting the heat to the wood. Given the size of the pieces in full size boat building, steaming in a steam box is a good way to heat the wood through and through in order to soften the lignin in the wood which is what it is all about. Even so, dry heat is also used where possible, to avoid the hassles involved in dealing with steam and moisture. (The gondola builders of Venice use open fires to heat their planks for bending.) But why get wet if you don't have to and when you can put the heat exactly where you want it and easily apply more as you need it when bending the piece?
 
A clothes iron as Chuck uses works very well for heating strip wood to bend it on the flat ("edge setting" in boat building parlance.) and you don't have to mess with steam or boiling water which risks burns and wets the wood which then requires drying time and, if moisture remains, often makes gluing difficult. Actually, if you use PVA adhesive to glue your planks in place, applying heat with an iron on the outside of the plank at each glued frame or bulkhead will dry the PVA, effecting a much faster setting time. To obtain curves in another direction (not exactly a "compound curve," which something different than what you are talking about here) a clothes iron can be used, but a heated, curved former is probably more effective. Use the forum search engine. There are posts on ingenious ways to do this. Some use tin cans heated on the inside with a propane torch as a former. Some use a pipe heated with a torch on the inside. Some apply heat from an electric curling iron and press the wood into a form cut from a block of wood. Myself, I am partial to the now-no-longer-made-but-sometimes-available-on-eBay Aeropicola plank bending iron, which is something like an electric soldering iron with a French Curve shaped head on it that allows bending various radii with it. There are other types of electric plank benders sold today that do the same, although not as well, if reports are accurate. 
 
As Chuck has so accurately said, you need to bend your planks, or any bent piece, for that matter, to shape before you try to fasten them up. You can use the frames or bulkheads as forms for bending, but don't expect the planks to stay in place unless they are bent to shape before gluing in place.
 
I would greatly encourage anybody who wants to bend wood to read "the Bible:" Bending Solid Wood to Form (1957) U.S. Dept. of Agriculture - Forest Service. (39 pages.)  https://www.fpl.fs.fed.us/documnts/usda/ah125.pdf  Bending wood is a lot easier when you understand the science and mechanics of what you are doing. 
 
  https://www.ebay.com/itm/AEROPICCOLA-Torino-WELLER-SP40-Electric-Plank-Bender-Tested-Works-Italy/383829086822?hash=item595dff1266:g:DhoAAOSwnRpfvwFq   There's an Aeropiccola plank bending head mounted on a Weller soldering iron for a "buy it now" price of $40.00 on US eBay. I suppose the fact that the head is mounted on an aftermarket soldering iron makes a difference for some reason I can't fathom, since the Italian originals were mounted on Italian soldering irons that were nearly identical to the Weller, which may even be of higher quality, for all I know, but these suckers have been listing on eBay for $75 to $100 (solely because nobody is making them anymore) and anybody who has any plank bending to do would be nuts not to grab this one like right now if not sooner. 

Yes, I buy HSS number drills in small sizes in bulk as well now that they are easily available. Curiously, now I've a good supply, I rarely break one!

I can't imagine why anyone would want to try to use a "power chisel" to shape a mast. The easiest way to shape a spar is to use a plane to turn the piece into an octogon and then chuck it in a drill press or hand drill motor held in a vise and sand the dowel while it's spinning. A lathe is another obvious option, but, considering the tooling costs for taper attachment and steady rest and the setup time, planing and sanding is a lot easier. Particularly with the planing, building a "planing sled" jig for your desired taper angle will make turning out a large number of spars a piece of cake.
 
I don't do a lot of wood carving, but it seems to me that there isn't a hundred bucks worth of advantage to a vibrating chisel over a good set of well-sharpened hand carving chisels and I suspect there are a lot more blade shapes available with manual carving tool lines than with the power chisels. (It seems there only five blade shapes for the Micro-Mark model.)
 
If i had a hundred bucks to spend on a tool for shaping spars, I'd go first cabin and spend $85 on a Lie-Nielsen Model Maker's Block Plane, a high-quality recreation of the old Stanley No. 100 squirel-tailed model maker's plane and the rest on a sleeve or two of sandpaper.
 
https://www.lie-nielsen.com/products/Model Maker's Block Plane
 

Dry heat is all you need. There is no need, nor point to using, steam or moisture of any kind when bending wood unless you have to, and that's probably almost never when modeling. The steam or other moisture only serves the purpose of transmitting the heat to the wood. Given the size of the pieces in full size boat building, steaming in a steam box is a good way to heat the wood through and through in order to soften the lignin in the wood which is what it is all about. Even so, dry heat is also used where possible, to avoid the hassles involved in dealing with steam and moisture. (The gondola builders of Venice use open fires to heat their planks for bending.) But why get wet if you don't have to and when you can put the heat exactly where you want it and easily apply more as you need it when bending the piece?
 
A clothes iron as Chuck uses works very well for heating strip wood to bend it on the flat ("edge setting" in boat building parlance.) and you don't have to mess with steam or boiling water which risks burns and wets the wood which then requires drying time and, if moisture remains, often makes gluing difficult. Actually, if you use PVA adhesive to glue your planks in place, applying heat with an iron on the outside of the plank at each glued frame or bulkhead will dry the PVA, effecting a much faster setting time. To obtain curves in another direction (not exactly a "compound curve," which something different than what you are talking about here) a clothes iron can be used, but a heated, curved former is probably more effective. Use the forum search engine. There are posts on ingenious ways to do this. Some use tin cans heated on the inside with a propane torch as a former. Some use a pipe heated with a torch on the inside. Some apply heat from an electric curling iron and press the wood into a form cut from a block of wood. Myself, I am partial to the now-no-longer-made-but-sometimes-available-on-eBay Aeropicola plank bending iron, which is something like an electric soldering iron with a French Curve shaped head on it that allows bending various radii with it. There are other types of electric plank benders sold today that do the same, although not as well, if reports are accurate. 
 
As Chuck has so accurately said, you need to bend your planks, or any bent piece, for that matter, to shape before you try to fasten them up. You can use the frames or bulkheads as forms for bending, but don't expect the planks to stay in place unless they are bent to shape before gluing in place.
 
I would greatly encourage anybody who wants to bend wood to read "the Bible:" Bending Solid Wood to Form (1957) U.S. Dept. of Agriculture - Forest Service. (39 pages.)  https://www.fpl.fs.fed.us/documnts/usda/ah125.pdf  Bending wood is a lot easier when you understand the science and mechanics of what you are doing. 
 
  https://www.ebay.com/itm/AEROPICCOLA-Torino-WELLER-SP40-Electric-Plank-Bender-Tested-Works-Italy/383829086822?hash=item595dff1266:g:DhoAAOSwnRpfvwFq   There's an Aeropiccola plank bending head mounted on a Weller soldering iron for a "buy it now" price of $40.00 on US eBay. I suppose the fact that the head is mounted on an aftermarket soldering iron makes a difference for some reason I can't fathom, since the Italian originals were mounted on Italian soldering irons that were nearly identical to the Weller, which may even be of higher quality, for all I know, but these suckers have been listing on eBay for $75 to $100 (solely because nobody is making them anymore) and anybody who has any plank bending to do would be nuts not to grab this one like right now if not sooner. 

Bob is right - the Bible when it comes to bending wood.  This govt agency more than earns their keep.  We had a speaker from the Madison, WI lab speak at the 2007 NRG Conference.  After he explained what happens to wood when Ammonia is used to help to bend wood I am very sure nobody in attendance that day has ever used Ammonia again and hopefully has cautioned others not to use it.
 
An interesting ship related item - I visited the Wood Services Product lab in Madison when I participated in a building code class at the U of W - and watched some deflection testing of wood beams.  They had a full size hull section of several frame pieces and planking off to the side built by the shipwrights involved with the USS Constitution's 200th Anniversary rebuild.  It was built so the lab could design and test a method of gauging the wood condition of the hull while the before it was moved to the drydock.  Similar to the electronic way a metal hull's thickness is gauged.  Doing so allowed the shipwrights to have a very good idea of what had to be replaced before the ship was drydocked so plans could be made for the restoration.  The lab director said they were going to have to do something with it soon to free us space and that the shipyard didn't want it back.  I volunteered to take it off their hands but the govt is real fussy in how stuff is disposed of - it's probably still sitting there.   If you ever get a chance to see a wood column load tested until it shatters I guarantee you will be impressed.

Dry heat is all you need. There is no need, nor point to using, steam or moisture of any kind when bending wood unless you have to, and that's probably almost never when modeling. The steam or other moisture only serves the purpose of transmitting the heat to the wood. Given the size of the pieces in full size boat building, steaming in a steam box is a good way to heat the wood through and through in order to soften the lignin in the wood which is what it is all about. Even so, dry heat is also used where possible, to avoid the hassles involved in dealing with steam and moisture. (The gondola builders of Venice use open fires to heat their planks for bending.) But why get wet if you don't have to and when you can put the heat exactly where you want it and easily apply more as you need it when bending the piece?
 
A clothes iron as Chuck uses works very well for heating strip wood to bend it on the flat ("edge setting" in boat building parlance.) and you don't have to mess with steam or boiling water which risks burns and wets the wood which then requires drying time and, if moisture remains, often makes gluing difficult. Actually, if you use PVA adhesive to glue your planks in place, applying heat with an iron on the outside of the plank at each glued frame or bulkhead will dry the PVA, effecting a much faster setting time. To obtain curves in another direction (not exactly a "compound curve," which something different than what you are talking about here) a clothes iron can be used, but a heated, curved former is probably more effective. Use the forum search engine. There are posts on ingenious ways to do this. Some use tin cans heated on the inside with a propane torch as a former. Some use a pipe heated with a torch on the inside. Some apply heat from an electric curling iron and press the wood into a form cut from a block of wood. Myself, I am partial to the now-no-longer-made-but-sometimes-available-on-eBay Aeropicola plank bending iron, which is something like an electric soldering iron with a French Curve shaped head on it that allows bending various radii with it. There are other types of electric plank benders sold today that do the same, although not as well, if reports are accurate. 
 
As Chuck has so accurately said, you need to bend your planks, or any bent piece, for that matter, to shape before you try to fasten them up. You can use the frames or bulkheads as forms for bending, but don't expect the planks to stay in place unless they are bent to shape before gluing in place.
 
I would greatly encourage anybody who wants to bend wood to read "the Bible:" Bending Solid Wood to Form (1957) U.S. Dept. of Agriculture - Forest Service. (39 pages.)  https://www.fpl.fs.fed.us/documnts/usda/ah125.pdf  Bending wood is a lot easier when you understand the science and mechanics of what you are doing. 
 
  https://www.ebay.com/itm/AEROPICCOLA-Torino-WELLER-SP40-Electric-Plank-Bender-Tested-Works-Italy/383829086822?hash=item595dff1266:g:DhoAAOSwnRpfvwFq   There's an Aeropiccola plank bending head mounted on a Weller soldering iron for a "buy it now" price of $40.00 on US eBay. I suppose the fact that the head is mounted on an aftermarket soldering iron makes a difference for some reason I can't fathom, since the Italian originals were mounted on Italian soldering irons that were nearly identical to the Weller, which may even be of higher quality, for all I know, but these suckers have been listing on eBay for $75 to $100 (solely because nobody is making them anymore) and anybody who has any plank bending to do would be nuts not to grab this one like right now if not sooner. 

Dry heat is all you need. There is no need, nor point to using, steam or moisture of any kind when bending wood unless you have to, and that's probably almost never when modeling. The steam or other moisture only serves the purpose of transmitting the heat to the wood. Given the size of the pieces in full size boat building, steaming in a steam box is a good way to heat the wood through and through in order to soften the lignin in the wood which is what it is all about. Even so, dry heat is also used where possible, to avoid the hassles involved in dealing with steam and moisture. (The gondola builders of Venice use open fires to heat their planks for bending.) But why get wet if you don't have to and when you can put the heat exactly where you want it and easily apply more as you need it when bending the piece?
 
A clothes iron as Chuck uses works very well for heating strip wood to bend it on the flat ("edge setting" in boat building parlance.) and you don't have to mess with steam or boiling water which risks burns and wets the wood which then requires drying time and, if moisture remains, often makes gluing difficult. Actually, if you use PVA adhesive to glue your planks in place, applying heat with an iron on the outside of the plank at each glued frame or bulkhead will dry the PVA, effecting a much faster setting time. To obtain curves in another direction (not exactly a "compound curve," which something different than what you are talking about here) a clothes iron can be used, but a heated, curved former is probably more effective. Use the forum search engine. There are posts on ingenious ways to do this. Some use tin cans heated on the inside with a propane torch as a former. Some use a pipe heated with a torch on the inside. Some apply heat from an electric curling iron and press the wood into a form cut from a block of wood. Myself, I am partial to the now-no-longer-made-but-sometimes-available-on-eBay Aeropicola plank bending iron, which is something like an electric soldering iron with a French Curve shaped head on it that allows bending various radii with it. There are other types of electric plank benders sold today that do the same, although not as well, if reports are accurate. 
 
As Chuck has so accurately said, you need to bend your planks, or any bent piece, for that matter, to shape before you try to fasten them up. You can use the frames or bulkheads as forms for bending, but don't expect the planks to stay in place unless they are bent to shape before gluing in place.
 
I would greatly encourage anybody who wants to bend wood to read "the Bible:" Bending Solid Wood to Form (1957) U.S. Dept. of Agriculture - Forest Service. (39 pages.)  https://www.fpl.fs.fed.us/documnts/usda/ah125.pdf  Bending wood is a lot easier when you understand the science and mechanics of what you are doing. 
 
  https://www.ebay.com/itm/AEROPICCOLA-Torino-WELLER-SP40-Electric-Plank-Bender-Tested-Works-Italy/383829086822?hash=item595dff1266:g:DhoAAOSwnRpfvwFq   There's an Aeropiccola plank bending head mounted on a Weller soldering iron for a "buy it now" price of $40.00 on US eBay. I suppose the fact that the head is mounted on an aftermarket soldering iron makes a difference for some reason I can't fathom, since the Italian originals were mounted on Italian soldering irons that were nearly identical to the Weller, which may even be of higher quality, for all I know, but these suckers have been listing on eBay for $75 to $100 (solely because nobody is making them anymore) and anybody who has any plank bending to do would be nuts not to grab this one like right now if not sooner.