Fin Cutting Method

[flying_silverad]

I am toying with the idea of incorperating a different method for cutting fins in a kit than what's normally offered and would like some feedback. First, let's assume that laser cutting is an option but is NOT elected for the kit for whatever reason. Having said that, cutting the fins is the course and this is the procedure.

The normal single fin pattern is replaced with a single sheet (with multiple fin patterns printed) that is glue sticked directly to the balsa. The sheet has all of the fins printed on it. You simply cut the all of the fins out as you normally would, but without all the tracing hassles. The nice thing is, no tracing, and every fin print is the same.

Then, you can either peel the paper off, or have the option for applying another sheet to the other side (before cutting) so that you have a cut fin, with two finished sides. No sealing, just sand the edges as necessary.

These fins would be small...for LPR.

Feedback?

 

[flying_silverad]

Oh yea... the glue stick would be inluded in the kit.

 

[Silverleaf]

John,

Will the glue stick bond hold the paper permanently - enough to paint, seal etc. ?

If so, this is a banner idea. I like !

8)

 

[DynaSoar]

Originally posted by flying_silverad
I am toying with the idea of incorperating a different method for cutting fins in a kit than what's normally offered and would like some feedback. First, let's assume that laser cutting is an option but is NOT elected for the kit for whatever reason. Having said that, cutting the fins is the course and this is the procedure.

The normal single fin pattern is replaced with a single sheet (with multiple fin patterns printed) that is glue sticked directly to the balsa. The sheet has all of the fins printed on it. You simply cut the all of the fins out as you normally would, but without all the tracing hassles. The nice thing is, no tracing, and every fin print is the same.

Then, you can either peel the paper off, or have the option for applying another sheet to the other side (before cutting) so that you have a cut fin, with two finished sides. No sealing, just sand the edges as necessary.

These fins would be small...for LPR.

Feedback?

Would it perhaps be beneficial to glue the patterned paper to one side, unpatterned paper to the other side, and leave it on after cutting? Finishing would be easier, and the strength would probably be good up through MPR, especially if it were basswood.

 

[SecretSquirrel]

Originally posted by flying_silverad


The normal single fin pattern is replaced with a single sheet (with multiple fin patterns printed) that is glue sticked directly to the balsa. The sheet has all of the fins printed on it. You simply cut the all of the fins out as you normally would, but without all the tracing hassles. The nice thing is, no tracing, and every fin print is the same.

Then, you can either peel the paper off, or have the option for applying another sheet to the other side (before cutting) so that you have a cut fin, with two finished sides. No sealing, just sand the edges as necessary.

That's the way I do it. I scan in the fin pattern from a kit and layout a cutting sheet. I then print it out and glue it to the balsa. Laminate the second side, cut out the fins and then sand the edges.

 

[SecretSquirrel]

Originally posted by Silverleaf
John,

Will the glue stick bond hold the paper permanently - enough to paint, seal etc. ?

If so, this is a banner idea. I like !

8)

The Elmer's white glue stick will if you give it a couple hours dry time before cutting. It even holds the paper on while I sand the edges of the fin round.

You can seal the paper with Aero Gloss dope before painting for a really nice finish. Brush on 3 coats and then lightly sand with 600 grit paper.

Here yopu can see fins finished in this manner, you can even see an unpainted kit with the paper lamination still visible.

https://www.aarg.org/nsl/rogers/mediafiles/l2.jpg
https://www.aarg.org/nsl/rogers/mediafiles/l1.jpg

 

[qMaxx]

Doggone it!

I wasn't going to say anything for awhile yet 'cause I'm still working on stuff, but I'm planning on offering a few kits after the beginning of the year (it's gonna take me that long to get the funds needed to start this thing up), and one of the features I'm planning to use is having the patterns printed on sticky paper that you would just stick to the sheet wood and cut out, then just peel off the paper.

The only reason I went that route is because laser cut fins and detail parts are just out of the question financially. I've already got 8 different sets of plans drawn up and am now working on writing up the instructions. Some are of models I built and flew a few years ago, so I know they'll work, but others will need to be built and tested.

Anyway, like flying_silverad said, would people go for this or not? On mine, the patterns should be removed, requiring the normal tedious filling. However, some planned kits will not require any fin filling.

f_s, please don't think I'm trying to steal your idea...I think it's just a case of parallel thinking...

 

[flying_silverad]

Originally posted by Silverleaf
John,

Will the glue stick bond hold the paper permanently - enough to paint, seal etc. ?

If so, this is a banner idea. I like !

8)

There would be an option for either way, permanent or peel it back off. Basically, just depends on how long you wait. I'm also playing with the idea of self adhesive paper, but I don't think it has the adhesive properties needed.

 

[flying_silverad]

Originally posted by DynaSoar
Would it perhaps be beneficial to glue the patterned paper to one side, unpatterned paper to the other side, and leave it on after cutting? Finishing would be easier, and the strength would probably be good up through MPR, especially if it were basswood.

Yep...that's what I meant. But you would have the option of either peeling it off, or leaving it on making the decision prior to cutting.

 

[flying_silverad]

Originally posted by qMaxx
Doggone it!

I wasn't going to say anything for awhile yet 'cause I'm still working on stuff, but ..........

f_s, please don't think I'm trying to steal your idea...I think it's just a case of parallel thinking...

Not at all...whatever makes the hobby better I say. This is the greatest think tank in rocketry. Besides, I don't think I'm the first person with this idea.

Anyway, I know it feels. When I was 8, I came up with this idea of Hydrogen powered cars and my teacher thought I was Whacked....go figure.

The plan here would be to print the sheet in such a way, that all you do is orient it to one end of the fin stock, peel, stick and your done. Grain refrence will be given (to show importance) but is already taken care of through the printing format.

 

[qMaxx]

Originally posted by flying_silverad
The plan here would be to print the sheet in such a way, that all you do is orient it to one end of the fin stock, peel, stick and your done. Grain refrence will be given (to show importance) but is already taken care of through the printing format.

Yeah...I have one planned kit that uses balsa, bass, and plywood in several thicknesses, so basically the builder would cut out the entire pattern sheet for a particular wood/thickness (noted on the printed pattern, as well as the grain direction), peel off the backing and lay it on the material, cut out the parts, peel the paper from the cut out parts, then attach/finish the parts as needed. The pattern sheet and the stock it will be placed on are the same size, to also help prevent mistakes.

I originally thought about doing it the way you are thinking, but I wasn't thinking about using glue sticks, so I figured by using regular white or wood glue that the fins would warp. That's when I thought about the self-adhesive paper.

BTW, thanks for the link to U-Line in your other thread. I'm definitely going to check them out.

 

[seo]

Originally posted by SecretSquirrel
That's the way I do it. I scan in the fin pattern from a kit and layout a cutting sheet. I then print it out and glue it to the balsa. Laminate the second side, cut out the fins and then sand the edges.

What weight of paper do you use?

 

[flying_silverad]

Originally posted by qMaxx


BTW, thanks for the link to U-Line in your other thread. I'm definitely going to check them out.

No problem.
Truthfully, I like the idea of peeling off the paper afterwords the best, I think that may be the way to go.

 

[shockwaveriderz]

could you use preprinted paper and or color paper using this idea?

I gather the idea is to pre-print the fin shapes unto an adhesive backed paper? to act as a template? My suggestion would take it one step further...if the adhesive sheets you attache to balsa was pre-colored and or pre-printed then in addition to the person using it as a template it would ahve the dual fucntion as adding "decoration" to the model and also strength depending on the adhesive/paper used......

 

[rbeckey]

I have tried using adhesive backed paper for finishing/strengthening fins, but found that eventually it bubbles or lifts. The paper was labeled "Permanent" adhesive, but I guess that refers to a completely smooth, hard, flat surface. I have had good results gluing paper to fins using wood glue or epoxy.

 

[qMaxx]

Originally posted by shockwaveriderz
could you use preprinted paper and or color paper using this idea?

I gather the idea is to pre-print the fin shapes unto an adhesive backed paper? to act as a template?

Correct.

My suggestion would take it one step further...if the adhesive sheets you attache to balsa was pre-colored and or pre-printed then in addition to the person using it as a template it would ahve the dual fucntion as adding "decoration" to the model and also strength depending on the adhesive/paper used......

That's an idea, but not something I'm able to do as I don't have much of an imagination for creating cool details. Besides, on one of my designs, I'd rather let the builder create his/her own color scheme/details, etc.

Also, as rbeckey mentioned, adhesive backed paper will eventually curl off or otherwise start to look bad after awhile. Gluing would be better, but then you have to worry about warpage. Epoxy would probably be better than white or wood glue, but that seems to be more trouble than it's worth. You COULD have sticky paper stay on the wood, but it would involve sealing the wood to give a good surface for the adhesive to stick to, and that kinda defeats the purpose.

 

[shockwaveriderz]

maybe a 2 part/step sysem would work? for example have the modler apply a thin layer of white or yellow glue to teh fin and let it dry..apply the paper and use an iron on low....this would re-melt the glue allowing it to fill the grain while keeping the paper from curling and such.....

maybe we need to invent a paper that has a white/yellow thin film as the adhesive abd then you could just iron it on in one step...

or better yet just quit using wood products completely for the fins and use G-10 fiberglass..... yes it might cost most but the advanatges out weigh the costs associated with having to fill and sand the wood products, the wood products have less strength and therefore do not last as long as the G-10 fiberglass would....plus the ideas of color adhesive sheets then would work fine with the underlying material....

perhaps in stead of g-10 you might be able to use a foam /paper backing material?

don't know just doing some mental gymnastics....

 

[SecretSquirrel]

Originally posted by seo
What weight of paper do you use?

I just use regular 20 lb. stock

 

[qMaxx]

Originally posted by shockwaveriderz
maybe a 2 part/step sysem would work? for example have the modler apply a thin layer of white or yellow glue to teh fin and let it dry..apply the paper and use an iron on low....this would re-melt the glue allowing it to fill the grain while keeping the paper from curling and such.....

Again, you still have the warpage problem. It's difficult to apply glue to BOTH sides of the fin, especially quickly enough to prevent warping.

maybe we need to invent a paper that has a white/yellow thin film as the adhesive abd then you could just iron it on in one step...

Now THERE'S an idea...

or better yet just quit using wood products completely for the fins and use G-10 fiberglass..... yes it might cost most but the advanatges out weigh the costs associated with having to fill and sand the wood products, the wood products have less strength and therefore do not last as long as the G-10 fiberglass would....plus the ideas of color adhesive sheets then would work fine with the underlying material....

perhaps in stead of g-10 you might be able to use a foam /paper backing material?

don't know just doing some mental gymnastics....

Actually, a couple of my designs use G10. For built up fins (the skins), or just fins for a 3/4fnc-style rocket, G10 is fine. However, for some rockets, especially scale designs, G10 is too heavy and too difficult to work with (diamond airfoils and such) exclusively. Which is part of the reason why I will still have some balsa/bass/plywood parts that will need to be cut from sheet stock. Hence the need for patterns.

 

[SecretSquirrel]

I may be wrong here, but maybe John suggested the glue stick in his first post because the glue stick doesn't tend to warp the balsa.

For what it's worth, I think the original idea posted is great.

 

[Stymye]

mabey try Weld Bond..works great with paper,transitions,wood ,plastic,looks,smells, and applies like white glue and dries crystal clear,sandable, and the manufactor claims it makes an excellent primer coat once sanded

..I used it for red and yellow paper on some nike smoke fins that was 3 years ago and they have yet to peel

...just annother suggestion to toss in the mix

 

[shrox]

I have been thinking about using full sheet white labels, stick them on, cut out the fin and leave the paper on if you want a little extra strength.

shrox

 

[OKTurbo]

I've had good luck using Mod Podge Matt Finish for sticking paper onto fins for strength and filling...

I paint it on with a brush. Apply the paper. Squegee out the excess with an old plastic Starbucks card. It cleans up with warm water.

John

 

[limd21]

If you go the self adhesive route, do some testing to see how it holds up to various glues and paints. I've experimented with various self-adhesive label papers over the years and some work much better than others. Interestingly, the labels UPS uses for their packages seem to be the best I've found in terms of permanence (resistance to peeling or bubbling when painted). Unfortunately, I can't imagine how you'd find a source for this material in the raw.

When I use paper laminated balsa, I first sand on the airfoil (e.g rounded leading edge, tapered trailing), then wrap the whole works in paper. This helps add a good bit a durability to the sanded edges. For the sharp trailing edge, which can be particularly vulnerable, I also wick in a bit of the super thin CA glue to add some extra strength.

 

[wwattles]

Originally posted by limd21
For the sharp trailing edge, which can be particularly vulnerable, I also wick in a bit of the super thin CA glue to add some extra strength.

I do the same thing, but use alcohol-thinned epoxy. It seems to reduce some of the brittleness while adding durability.

Overall, I've had the same experience with the paper lamination - some papers work better than others, and some adhesives are far superior to others. One that's worked fairly well for me is the Elmers Craft Bond spray glue. It's designed for use with paper where warping or paper-wrinkle is not an option.

Full-sheet Avery Label Paper has worked well for small fins.

WW

 

[Sirius Rocketry]

....Paper reinforcing material. One of those things I had to have. Was part of kits sometimes, and even in the catalog.

Was a great way to reinforce things, ans you have a great idea going! Do it!

Dave