Rattlesnake 1780 by captgino - 1/4" scale (1/48) - Harold Hahn Method

[captgino]

All frames are now glued. Next step: pattern cutting and gluing. ✂️✂️

 

[captgino]

Time to glue some paper.... 

[stuglo]

Have you used this method of  shaping/ marking frames before. I found that when I cut out the paper pattern as you have done, they tended to distort when glued to the wood. I therefore stuck them "whole" then cut them together with the wood. I hope to start my Rattlesnake in a couple of months, so I want to share your experience

[mtaylor]

Stuglo is right.  I had the same issue with Licorne, so I ended up gluing the whole sheet to the blanks and then when the glue dried, cutting away the excess.

[captgino]

9 hours ago, stuglo said:

Have you used this method of  shaping/ marking frames before. I found that when I cut out the paper pattern as you have done, they tended to distort when glued to the wood. I therefore stuck them "whole" then cut them together with the wood. I hope to start my Rattlesnake in a couple of months, so I want to share your experience

Darn, a few hours wasted... The bigger problem is getting new copies in this lock-down world we live in 🤔

I will see out bad it is.

[stuglo]

Its cheap to photocopy everything several times- I use my simple home printer

[dvm27]

Yes, and also mark a center line in the middle of the pattern between top timbers and glue sheet over a jig with a corresponding center line. Paper is easily distorted One frame slightly askew will change the shape of the hull during the fairing process.

 

 

 

[Schooners]

JP,

I am in a similar place as you in my build and thought I would pass on my experience shaping the frames.  Take it all with a grain of salt.

 

I cut the patterns out about a 1/16 wide of the outside line and leave the inside of the pattern intact as others have mentioned.  I use Scotch Craft stick to attach the patterns to the frames, it is just a glue stick.  The advantage is that is holds well, you can move the pattern around a bit when you are installing the pattern and is easy to remove later with a slight wetting with water and a paint brush.  The trick here is to put the glue stick on the frame, NOT the paper.  When putting it on the paper the paper will soften and distort.  With the glue on the frame you can carefully lay the pattern down. I start at the top and slowly press it down with a bit of motion to the outside with both thumbs simultaneously. When done, you can tap the paper in the middle of the frame and it should be tight and you should get a thump like tapping a drum.

 

A note: Tony Kay recommends Uhu (a solvent based glue in a tube) which is used by card modellers. I ordered some, but I was done by the time Amazon delivered it so I do not have any personal experience with it. 

 

Before I talk about the cutting and shaping the frame, I would recommend making three to five dummy frames out of scrap wood, and glue templates to them and practice the shaping.  It took me about three frames to get my technique down and by the fifth frame I was a master at the band saw and spindle sander.  Unfortunately, my first three frames look a little ragged.

 

I cut out the outside of the frame first on the bandsaw leaving about a 16^th”, then disk sanded as much as I could removing the white paper outside the black line of the frame. I had better control of the disk sander than the spindle sander. I left the line thickness on the frame as I figure I will sand a little more one the frames are all glued into place.  I then used the spindle sander to get the parts that I could not do on the disk sander.  I do not have an oscillating spindle sander so the paper template is not cut off cleanly as it is on the disk sander.  I would completely shape the outside of the frame before I cut out the middle of the frame so the frame is more robust while working on the outside; my frames are very thin and I worried about working the outside after the inside was cut out.

 

At this point I marked the frame number with pencil in an area that will not be seen later, I mark at the bottom where my frame meets the keel.  I need to mark the waterline on the frame as well, but you probably don’t need to do this.  You will be building the ship upside-down right?

Then I cut out the inside of the frame on the band saw.  I got pretty good with the band saw and could cut accurately close to the line, but you still need to leave a bit to sand as the saw cut is ragged. Then I spindle sand the inside. 

 

Finally, I used a Dremel with a drum sander to taper the frames by hand as needed.  My templates have dashed lines for the far side showing the amount of taper required (as do yours). I sand down to the dashed line first to place a chamfer on the outside, then flatten the outside of the frame to match the required taper.  The same thing is done inside of the frame.

 

I double check all pencil marks needed are on the frame, then I dampen the paper with water and peel off the paper.  I wet it once again and use a paper towel to rub off the last of the glue.  Now, I waited a day for the water to completely dry.  I then gave the frame a final light sanding.  Then I drilled the holes for the dowels, glued in the dowels holding the futtocks together.  Let the glue dry, trim and sand.  Then Rejoice!

 

I am sorry if this is a bit long winded and may all be obvious, Good Luck

[captgino]

Thank you for this detailed information. I am sorry I completely missed it and did not respond sooner. 

I agree with you. I think it would be better to put the glue on the wood to avoid having The Paper distorting. 

 I bought some rubber cement from Elmer, and I am trying it how to see how it holds the patterns. 

I am redoing the stem on my siren and I'm using it there I will see if it works out better. 

 

Are the dotted lines representing the front or the back of the frame?

Did you tilt at all your bandsaw to get closer to the final shape? 

[Schooners]

JP,

 

I tried Elmers rubber cement, but didn't have very good luck with it.  It didn't seem to hold well enough, you may have better luck. The nice thing about rubber cement is that it rubs cleanly off and you don't need to wet the frame to remove the pattern.  I printed out frame patterns for both sides of the frame--However, I had a hard time to perfectly aligning patterns on each side of the frame so I abandoned that approach.   The dotted lines are for the far side bevel as if you could see through the frame, and the solid lines are for where the bevel ends on the near side.  I put the pattern on the side of the frame that has the taper on the out side of the frame.  Then I bevelled the out side first.  That is, a frame near the bow I would put the pattern on the front side, and a frame near the aft of the ship I would put the pattern on the aft side of the frame.  That way I always have a solid line to bevel to on the outside that gets beveled, then the inside I do afterward by eye to match the dashline.  I do not use the bandsaw to bevel the frame as I have much more control using the spindle sander. Also the bevel is not uniform up and down the outside of the frame so it would be hard to set the angle with the bandsaw. So I rough cut the frame flat on the bandsaw.  Then I spindle sand to the outside lines all the way around the frame.  Then, I spindle sand the bevel by holding the frame at an angle.  I start with the frame with a steeper angle to the spindle plate and take the wood down to the inside line, Then lower the frame to table angle and take another delecate pass on the spindle sander until the bevel starts on the inside line on the top, but does not take any wood off on the bottom side.  It takes a bit of practice, but is easy to control once you get the hang of it.  Make some scrap frames and practice.

 

Good Luck.  

[captgino]

Thank you all for your comments and recommendations. I have started to glue some of the patterns. No distortion on the ones I did so far. 

You guys are right. It has a tendency to distort easily if you are not careful. I am being very careful and slow when gluing the pattern to minimize impact. It took me about 4 hours to glue 18 frames. 

I am going to make some additional photocopies to support the frames with a wider pattern. 

I also unfortunately discovered that I have a few frames in the middle of the ship that will need to be remade, as the pattern is too close to the edge or on it. 

I think it's a situation where small mistakes in the angles added up and end up distorting the frames. 🤬

Beginner stupidity!!!! 

I am in the process of surveying the damage. 😢

 

Edited May 5, 2020 by captgino

[Schooners]

JP,

One quick suggestion, and ignore me if you have already done this.  Measure the openning at the very top of each printed frame extension from the outside line on each sided as accurately as possible, then compare with the printed plans.  It is possible that the 'U' shaped piece of paper template splayed open or closed ever so slightly as you glued them to the frame.  I leave the template intact and don't cut out the inside of the 'U' until the paper template is glued in place.

 

Looking Great, I am impressed by the care and precision you are attacking this project. 👍

[captgino]

Thank you for the recommendation. Here are the last few templates glue to the frames. 

 

[captgino]

Starting to cut the frames. 

 

Stopped after 4 and ordered some new blades which will provided smoother cuts. 

[captgino]

New blades new cuts. Here is yesterday's work.

 

[Sonofagun]

On my Hahn RATTLESNAKE, I placed the first and last whole frame the first thing. Supported them to make certain they are 90 degrees from the frame jig. Then you can place the keel,WITHOUT GLUING IT, To help keep the frame spacing from top to bottom. I don't know if you are already doing this. Just thought I would throw the suggestion out there.

[captgino]

Thank you for the recommendation. I am done with 80% with the sanding of the frames. It still need to get the bevel and various angles figured out. 

I am assuming that you first put together the stem and deadwood  with the keel, right? 

[Sonofagun]

Yes, I did assemble the entire keel, stem and aft deadwood and used it to help keep the frame spacing.  I think the trickiest part of the hull was assembling the hawse pieces. Hahn’s drawings do a very decent job of preparing the individual pieces.

i got very lucky and only had to redo them once!  The model is a great deal of fun and will keep you occupied for hours. There were a few times when I would get frustrated and need to take a break. But you get hooked by the bug...

If you haven’t purchased THE FULLY FRAMED SHIP MODEL series of books by David Antscherl and Greg Herbert, I would highly recommend it! At least to start with the first book of the series. It has an unbelievable amount of information that is useful for any ship modeler. Very well written. Just a suggestion. I wish I had purchased and read them much sooner than I did!

 

[Mike Y]

JP, hope your build progresses nicely!

Just a small word of caution in that critical moment - check the alignment of the top part of your frames, next to the cutoff sections. These areas are thin, and would be very visible once the hull is flipped over. Luckily cutoff sections can be moved around a bit to compensate for it, but it needs to be done before frames are glued to the jig. Some strip of wood would help to check the alignment.

I was not so careful during that step and still see the results of that mistake..   

[frank shurick]

I like what you are doing with the frame assembly clamping. Very solid technique that reduces the possibility of the 

individual futtocks moving during clamping and while drying. I am about to embark on making my frame assemblies and

will use your method. Thank you.

[Roger Pellett]

I built a POF model of the 1812 era New York Pilot Boat Anna Maria many years ago.  I used Howard Chapelle drawings that I adapted for use with the Harold Hahn method.

 

It is my experience that it is not necessary to bevel sawed out frames before they are erected.  It is also much easier to bevel them after erection when the shape of the entire hull becomes apparent.  The keel, stem, and sternpost should be installed first to stabilize the structure.

 

Harold Hahn did not bevel frames before hand on his earliest models.  He adopted this step later as a labor saving step.

 

Roger