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Tacking templates to balsa stock

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kruland

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Hi all,

I was wondering what people use to temporarily tack paper templates to balsa stock. I want to be able to remote the paper and not have a gooey mess to clean up.

Thanks much

kruland
________
MAZDA CAPELLA HISTORY
 
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kruland

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I wouldn't have thought something so simple would work. I'll steal it from my kids. Thanks.
________
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powderburner

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Specifically, T-top straight pins, like you use for building balsa model airplanes.

I use CA to toughen the paper pattern. I wick it into the paper along all the edges (before I cut the pattern from the sheet it is printed in). Sometimes I wick CA into the entire area of the pattern, if I want to keep the fin pattern for use later and want to "preserve" it a little better. Otherwise I mark a few dots in the middle of the fin area and put drops of CA on those dots.

When the CA sets I cut out the fin pattern, rough cut the balsa stock, stack the pieces with the pattern on top, and pin through the dots to hold the stack together while I finish sanding the edges to the fin pattern. After you finish, pull the pins and fill with spackle (along with the rest of the balsa grain).
 

MarkII

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Pinning balsa fins together to stack-sand them is a venerable technique that should be in everyone's tool kit. It is absolutely the best way to get hand-cut fins to come out with totally identical shapes. With smaller fins, though, try to find really thin pins and use care when you place them, or else you will get split fins.

Great suggestion, powderburner! A classic technique that is still one of the best!

MarkII
 

JRThro

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Pinning balsa fins together to stack-sand them is a venerable technique that should be in everyone's tool kit. It is absolutely the best way to get hand-cut fins to come out with totally identical shapes.
That's assuming I could make vertical cuts through even one layer of balsa, let alone 3 or 4! When I cut out fins, the edges almost always have a slant to them.
:eek:
 

BobH48

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That's assuming I could make vertical cuts through even one layer of balsa, let alone 3 or 4! When I cut out fins, the edges almost always have a slant to them.
:eek:
That's why you would cut them out slightly oversize and sand the stack to final shape.
 

georgegassaway

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Rubber Cement

NOT to be confused with Contact Cement

- George Gassaway
 

Pat_B

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Me too on the rubber cement. I usually apply it to the paper template then press it onto the fin. That prevents the balsa from trying to soak it up.

In my case, I'm usually cutting out fins that have already been sealed in some way (usually vac-bagged w/epoxy & fg) and the rubber cement has no chance of soaking in anyway.
 

Micromeister

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Hi all,

I was wondering what people use to temporarily tack paper templates to balsa stock. I want to be able to remote the paper and not have a gooey mess to clean up.

Thanks much

kruland
Kruland:
I make a cardstock or cardboard template of my fin patterns than soak it with thin CA to make the template permanent. then simple hold the template in place while I draw around it with a stabilo or very soft lead pencil. no need for any kind of tape or adhesive at all.
Photos show templates used on Clear Polycarbonate but I use exactly the same process on Balsa and basswood as well.
hope this helps.
 

troj

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then simple hold the template in place while I draw around it with a stabilo or very soft lead pencil. no need for any kind of tape or adhesive at all.
I do the same.

For some fins that I need to cut a bunch of (over 100), I used the paper template to make a Lexan template, so that it's more durable. But for typical models, John's method has never caused me issues.

-Kevin
 

Micromeister

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I do the same.

For some fins that I need to cut a bunch of (over 100), I used the paper template to make a Lexan template, so that it's more durable. But for typical models, John's method has never caused me issues.

-Kevin
Quite ture Kevin:
For Fin patterns used on a much more regular basis, I've used Matte boards, Heavy Sho-card, Tempered hardboard, Polycarbonate(Lexan) or gone as far as .040" alumimum templates for "Standard size" PD & SD model fins and fins for Eggloft, Alititude and Flex-wing Boosters.
Whatever the material, just make sure the edges can hold up under the repeated pressure of the pancil without distorting the lines.
 

JAL3

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Sometimes simple is good. I never even thought about using the glue stick but when I read it, AHA!

I bought a pack yesterday and tried it out on a template I drew last night for the MMX head I'm working on. It did great for what I wanted. It's not permanent but does hold the template in place while I did the cutting and sanding into the rought shape.

Thanks for the tip.
 

Trident

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Related suggestion, to speed up fin cutting, along with templates:

If I have simple fins whose edges are straight, I usually cut them out well outside the final line, and not worry about cutting them precisely. I then use a small tabletop disc/belt sander to sand the stack down to the final outline. Even with curved edges, if you have a narrow enough belt, you can follow the curves.

All fins have super-straight edges, all identical, and really fast to make.

My hobby belt/disc sander is a Dremel table top model, with a 5" disc, and a 1" wide vertical belt. The narrow belt is really a great feature. It is perhaps one of the most used power tools in my shop, with maybe the exception of my drill press.

By the way, I use a hobby bandsaw to rough cut my fins, most of the time. After I get the typical 3-4 cut, I stack them, and either cut along the fine lines on the top fin, or add a paper template, if I really feel the need. If the fins all are aligned on a sheet, I can usually cut out all the fins in less than a minute. I'll zip the first one off the sheet, then the next, and so on. Then I run all of them thru for the a 2nd cut, then the 3rd, etc.
 

MarkII

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That's assuming I could make vertical cuts through even one layer of balsa, let alone 3 or 4! When I cut out fins, the edges almost always have a slant to them.
:eek:
No, that's not it. You cut each fin out first, stack them all together, push some thin pins through the stack and then sand the edges so that they exactly match on all of the fins. You should do this because no matter how careful you are, you will not get a set that exactly matches when you hand-cut fins. (I tend to do that same thing as you when I cut out fins.) I just pinned and sanded a set of balsa fins earlier this evening and the technique worked great, as always. You can try to just grip the stack of fins tightly with your fingers when you match-sand them, but pinning them together works much better. The fins can't slip out of alignment if they are pinned together, and you can rotate the stack to work on difference sides without having to realign the edges each time. Use thin dressmaker's pins (the kind with the little colored ball on the head). The pinholes are barely visible afterward, and they fill right in when you apply your balsa grain filler. This is an old model aircraft wing builder's trick.

MarkII

P.S. I don't use any power tools. Not enough money in the old hobby budget for them. I even cut out thin plywood (up to 1/4" thick) with a utility knife and a metal straightedge (and a lot of sweat). I have even cut up steel sheet with that method (so the edge doesn't curl). I'd love to get a drill press, a scroll saw and a disk sander (especially a disk sander) someday, when the finances permit it.
 
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Micromeister

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Why do you guys need to pin anything together? Raw woods have enough surface to surface friction with a very light amount of pressure between the fingers they pretty much stay together once stacked. Balsa and Basswood are especially good for this type stack sanding. Wafferglass, polycarbonates and plactic are a little trickier but can still be done this way.

For the majority of Micro, Standard and Large model rocket fins, I just hold the stack of fins between my fingers and sand on a sheet of sandpaper taped to a flat surface or a long sanding block. A sheet of Glass makes an Excellent and Dead flat surface for such activities. Move the fin stack NOT the sandpaper to do the work. Rotate the fins stack in our fingers to the next side and repeat until all sides are compeletely even. Micro to MPRs size fins, .005" waferglass to 1/4" Ply all work pretty much the same.
I generally start with the root edge then just rotate the fin stack around between the thumb and fingers until all sides are even. they can then be rounded and/or tapered as need.

If I have some really tough material or a big batch of fins or centering rings to sand (I generally like a stack of rings 10 or 20 at a time depending on thickness) I'll stack them with double faced masking tape between each layer rather then pins. Removing the tape immediately after shaping leaves no residue. This method allows a large or small stack of fins or rings to be sanded on a vertical sanding belt or wheel easily and quickly without poking unnecessary holes in or cracking the materials.
 
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MarkII

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Gripping the stack between my fingers doesn't work for me; the fins always move slightly in relation to each other. They do so especially when I hold the stack up to check my progress, or when I rotate it to sand another edge. Pinning is really simple and really easy, and it takes care of that problem. It's a classic model-building technique that I first read about during my early days in model rocketry back in the mid-1960's. Try it!

MarkII
 

Micromeister

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Don't need to as it would have no value for me since I guess i've learned over time how not to let the fins or rings slip while checking and rotating. It comes so quick and easy now it'd take 3 or 4 times as long to start using pins again.
Back in the stone age 60's when I was also building stick and tissue free flight planes, I used pins to hold stuff occasionally but never liked it because of the splitting and weakening of the wood. Later magnets came into vogue that gave me a pretty decent setup that could do 54" wing layups but again I always preferred just holding parts together while they set-up or during shaping and sanding. Guess it's all in what we get used to? Then again I generally don't need a fin alignment jig either guess i've been blessed being an archer doing fletching repairs has given me an eye for getting fins or feathers on straight LOL!
have you guys tried double faced masking tape?
 

MarkII

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Yeah, I don't use a fin jig, either. I have a well-calibrated eyeball ( :cyclops: ) that I developed many years ago during countless drawing and painting classes, and then subsequently when I worked as a printer. It must work, too, because my rockets don't spin. Pinning balsa is a great time-saver. Yes I can sand edges to be even without resorting to pinning the material, but it takes longer. I try to work smarter, not harder (and sometimes I even succeed). I don't get splits in the material because I only use a few pins (usually three) and I use the thinnest ones that I can find. It only takes a few seconds to pin the parts, and then I can just sand them without having to worry about whether I am keeping the edges even all the way around. It's a very reliable technique and I'm glad that the opportunity came along to mention it.

MarkII
 

luke strawwalker

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Why do you guys need to pin anything together? Raw woods have enough surface to surface friction with a very light amount of pressure between the fingers they pretty much stay together once stacked. Balsa and Basswood are especially good for this type stack sanding. Wafferglass, polycarbonates and plactic are a little trickier but can still be done this way.

For the majority of Micro, Standard and Large model rocket fins, I just hold the stack of fins between my fingers and sand on a sheet of sandpaper taped to a flat surface or a long sanding block. A sheet of Glass makes an Excellent and Dead flat surface for such activities. Move the fin stack NOT the sandpaper to do the work. Rotate the fins stack in our fingers to the next side and repeat until all sides are compeletely even. Micro to MPRs size fins, .005" waferglass to 1/4" Ply all work pretty much the same.
I generally start with the root edge then just rotate the fin stack around between the thumb and fingers until all sides are even. they can then be rounded and/or tapered as need.

If I have some really tough material or a big batch of fins or centering rings to sand (I generally like a stack of rings 10 or 20 at a time depending on thickness) I'll stack them with double faced masking tape between each layer rather then pins. Removing the tape immediately after shaping leaves no residue. This method allows a large or small stack of fins or rings to be sanded on a vertical sanding belt or wheel easily and quickly without poking unnecessary holes in or cracking the materials.
Yep that's how I do it...

Sometimes I have to shift my grip or realign the fins a bit, but once you make several passes, they start to line up really easily and then finally all stay stacked neatly as you switch positions.

Whatever works best for ya though... :) OL JR :)
 

judo

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Trident,

I have that same belt/disk sander combination. I can't stack sand my fins very well at all because dispite all my tweeking, I can't seem to get an arc out of the belt.
 
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