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Intruder
05-31-2008, 08:02 PM
I'm about to start on my Interceptor-E, and I am wanting to build it without the reinforcing struts. There are some things I would like to know about the Avery label paper everyone talks about.


How much strength does it add to the fin as compared to using thicker balsa (Avery laminated 1/8" fins as compared to unlaminated 3/16" balsa)?



Does it have serious problems lifting or bubbling in the middle after painting or after an extended period of time (like 5-10 years)?



What are some techniques to preventing such problems?



Are there any other significant advantages of the Avery label paper over thicker balsa (other than having to sand less area and the answer to question 1)?


All information is greatly appreciated.

Rocket Doctor
05-31-2008, 09:48 PM
The balsa fin reinforcements were added after many flights during testing. Having built one of the originals, I found the added balsa to be a pain, but, somehting needed for strength.

I think over time, in my opinion, the avery material would tend to dry out and the finish would come off.

The Interceptor can be built "stock" and with the decals added, it does look decent.

I'm sure there are other opinion as well.

Tau Zero
05-31-2008, 11:20 PM
I'm about to start on my Interceptor-E, and I am wanting to build it without the reinforcing struts. There are some things I would like to know about the Avery label paper everyone talks about.Intruder,

Here's part of my discoveries about the technique from way back in August 2006:

http://www.oldrocketforum.com/showthread.php?t=1042


How much strength does it add to the fin as compared to using thicker balsa (Avery laminated 1/8" fins as compared to unlaminated 3/16" balsa)?I'm not an engineer, so I can't give you hard and fast mathematical figures. The technique makes 1/16" fins surprisingly durable, and doesn't add hardly any weight (in contrast to using basswood instead of balsa fins, which would increase your fin weight 300%).


Does it have serious problems lifting or bubbling in the middle after painting or after an extended period of time (like 5-10 years)?

What are some techniques to preventing such problems?I haven't been doing it that long. CPMcGraw, do you wanna weigh in here?


[i]Are there any other significant advantages of the Avery label paper over thicker balsa (other than having to sand less area and the answer to question 1)?Try the method first, and then compare it to having to fill and sand about a million times. :rolleyes: (Sorry, did I say that out loud? :o )

As with everything else anybody tells you, your mileage may vary. ;) :D :p


Cheers,

CPMcGraw
05-31-2008, 11:21 PM
Intruder, one builder's perspective:



How much strength does it add to the fin as compared to using thicker balsa (Avery laminated 1/8" fins as compared to unlaminated 3/16" balsa)?
With thin balsa, like 1/16", I can see considerable strength in the composite structure. With 1/8" balsa, maybe not as great. It becomes more of a finishing issue than a strength issue.

Does it have serious problems lifting or bubbling in the middle after painting or after an extended period of time (like 5-10 years)?
I have a Laser and a Wizard, using computer paper and 3M-77 spray adhesive, going into 5 years without any delaminating. Admittedly, not exactly the same combination, and they don't get much flight time, but just from an age perspective, I'd say they're doing well. I don't think the self-stick adhesive of a label sheet is going to be that much different. Once the primer cures, they seem to be protected somewhat. UV is probably the killer for the adhesive...

What are some techniques to preventing such problems?
Sealing the outer edges with CA, for one. This will do more for preventing delaminating than anything else. Just be careful at the root edge; CA will block the end grain of the balsa, making it impossible for any of the yellow or white glues from penetrating. This may weaken the edge bond to the tube.

Are there any other significant advantages of the Avery label paper over thicker balsa (other than having to sand less area and the answer to question 1)?
No, not really; and you can save yourself some money by picking up the "house brand" label sheets instead of the Avery. A 25-sheet pack from Office Max is $10. Once the paper is sealed and primed, you cannot tell the difference.

If strength is needed, and you want something light, you can always go to a model airplane finishing method: Silk (or silkspan) and dope. It's like a twenties-era version of glassing, only much lighter. Dope (or clear lacquer) fills the weave of the fabric and firmly bonds it to the balsa, creating another form of composite structure. It has more strength than (label) paper, and doesn't add much weight. The primary disadvantage is the noxious VOC content.

Last possibility, use thin strips of CF tape as a reinforcement run in the same location as the balsa strip. If you then apply label paper over that, or even silkspan and dope, the CF tape will virtually disappear into the finish.

kelltym88
06-01-2008, 07:51 AM
Or, you could just go with an entirely different paint scheme.

Intruder
06-01-2008, 09:02 AM
The Interceptor can be built "stock" and with the decals added, it does look decent.


I agree. I've seen some "stock" Interceptor-Es that looked great. However, I don't want to go that route right now.

The information from CenturiGuy and CPMcGraw is very helpful. I have a lot to think about now. I still seem a little paranoid about using the label paper. I've started to toss around the idea of using computer paper and glue or the 3M Super 77 spray that I have. How fast does the 3M spray dry and does it suddenly "grab" like yellow glue does? I'm curious as I might use it some other rocketry applications.

Again, I would like to thank all of you for your input.

jetlag
06-01-2008, 09:48 AM
Intruder,
Save yourself all the hassel and just build with the reinforcements. I used them, but only after rounding them significantly to more of a slope than the rounded, squared off shown in the instructions. I used a belt sander to achieve a quite good-looking piece. After you glue them down on the wings, fill and sand as normal. You will achieve a furniture or automotive- smooth finish, and the decals are very easy to apply to it. The reinforcements look like little humps on the wings. I hope the pics help show better. ;) You can also see them in the vertical stabilizers as well.
Allen

Sorry for all that 'background noise' in some of the pics; my shop is a tad crowded!

pantherjon
06-01-2008, 10:11 AM
I built my Interceptor E without the re-enforcing strips on and with no paper lamination as well..It has flown 8 times now(all on reload E's and F's) with no significant damage to the fins..One of the pods was jarred loose on one of the landings..So save some time and just give the balsa a good sealing and you would be good to go..

Just one BAR's experience, I may be an exception and not the norm...

ghrocketman
06-02-2008, 10:16 AM
I'm just replacing my fins with hand-cut basswood, which may/may not be neccessary, but it sure looks a LOT better than those ugly bulges. :mad:
It will be heavier, but I have ZERO intention of flying anything this big with a D12 or with the pathetically weak thrust E9. Nothing less than an RMS E18 (more likely E28, F24, and F39) will be used to power mine.
I'd rather GLASS the balsa fins completely than have those bulges and that would be a LOT more work but sure would look a LOT cleaner.

Little things like correct length (at LEAST 2x entire rocket length) shock-cords and proper fin materials for mid-power would go a LONG ways to improving Estes kits.
Instead they continue to go the CHEAPO route (isn't the foreign labor in itself cheap enough?) instead of making a quality product.

CPMcGraw
06-02-2008, 11:21 AM
...I've started to toss around the idea of using computer paper and glue or the 3M Super 77 spray that I have. How fast does the 3M spray dry and does it suddenly "grab" like yellow glue does?...

3M-77 is a spray contact adhesive, meaning it needs to be sprayed onto both surfaces to be most effective. I can't remember if I did this myself, however, on either the Wizard or Laser. :o

It has a short "drying" time, but generally remains sticky even when dry to the touch. It grabs immediately (contact adhesive) so you don't get much of an option about how you position the paper. It's mostly a one-shot-at-it method. You also need to "burnish" the paper down to ensure complete adhesion. This is problematic, in that if you use the wrong tool, or press down too hard, you wind up with gouge marks that have to be filled later, and that somewhat defeats the idea of a no-surface-prep finish technique.

It's not impossible, it's not even that difficult once you know how to work with it, so don't let this discourage you from trying. It just takes a little careful preparation to get the paper aligned as it's being placed. I would recommend cutting the paper a bit oversized, and pressing the fin down onto that, instead of the other way around. Then, you just trim the excess from around the edges with an X-Acto knife. It seems to have fewer flaws in the end...

Intruder
06-02-2008, 12:33 PM
I've pretty much decided on using computer paper and glue for my lamination. I've laminated with cardstock and glue before, so I have a little practice. With the Interceptor-E being a $30+ kit WITH a 40% off coupon, I want to do something that I have tried before with some success.

barone
06-02-2008, 07:23 PM
I've pretty much decided on using computer paper and glue for my lamination. I've laminated with cardstock and glue before, so I have a little practice. With the Interceptor-E being a $30+ kit WITH a 40% off coupon, I want to do something that I have tried before with some success.
I used card stock and 3M spray. You're going to end up with a seam since one sheet (8.5X11) won't cover the entire fin. If you can get 8.5 X 14 or 11 X 17, you can get it seamless. I didn't trim the card stock until after it was applied to the fin so I didn't have to worry about getting it just right.

ga1ba2
06-02-2008, 07:52 PM
A little bit off topic but not much :rolleyes:
Got my Interceptor E friday and it was missing the "A" sheet balsa fins , emailed Hobbylinc but have not heard back yet. Any one else have problems with missing items?

barone
06-02-2008, 09:53 PM
A little bit off topic but not much :rolleyes:
Got my Interceptor E friday and it was missing the "A" sheet balsa fins , emailed Hobbylinc but have not heard back yet. Any one else have problems with missing items?
Mine had all the pieces. You'd have better luck with Estes Cutomer Service vice Hobbylinc since the kit was manufactured by Estes.

Rocket Doctor
06-03-2008, 04:01 AM
I used card stock and 3M spray. You're going to end up with a seam since one sheet (8.5X11) won't cover the entire fin. If you can get 8.5 X 14 or 11 X 17, you can get it seamless. I didn't trim the card stock until after it was applied to the fin so I didn't have to worry about getting it just right.

You could use a piece of poster board, it's certainly large enough.

ga1ba2
06-03-2008, 10:53 PM
Hobbylinc said they would send one as soon as possible.

Ikaros
06-05-2008, 03:34 PM
Intruder,
Save yourself all the hassel and just build with the reinforcements. I used them, but only after rounding them significantly to more of a slope than the rounded, squared off shown in the instructions. I used a belt sander to achieve a quite good-looking piece. After you glue them down on the wings, fill and sand as normal. You will achieve a furniture or automotive- smooth finish, and the decals are very easy to apply to it. The reinforcements look like little humps on the wings. I hope the pics help show better. ;) You can also see them in the vertical stabilizers as well.

I like your wing humps! At a Hobbyworks store near my job, they have both the original Interceptor and the larger E version. I almost bought the original Interceptor (because I had one as a kid in high school) but then I noticed the big E one, which I had never seen before in person. So this payday I'm thinking about getting one or both of them. I kind of like the look of the wing reinforcements. I thought it was there to add new surface detail to the original look, until I read here what they are really there for. But they do remind me of the buldges on real aircraft that cover sensors, etc.

So I'm also wondering if anyone building the smaller Interceptor have tried to duplicate all of the large E wing and rudder modifications on it? I think it would look cool myself and may try it if I select the original size Interceptor instead.

jetlag
06-05-2008, 05:16 PM
I like your wing humps! At a Hobbyworks store near my job, they have both the original Interceptor and the larger E version. I almost bought the original Interceptor (because I had one as a kid in high school) but then I noticed the big E one, which I had never seen before in person. So this payday I'm thinking about getting one or both of them. I kind of like the look of the wing reinforcements. I thought it was there to add new surface detail to the original look, until I read here what they are really there for. But they do remind me of the buldges on real aircraft that cover sensors, etc.

So I'm also wondering if anyone building the smaller Interceptor have tried to duplicate all of the large E wing and rudder modifications on it? I think it would look cool myself and may try it if I select the original size Interceptor instead.


Thanks, Ikaros!
If you do decide to duplicate the reinforcements on the smaller Interceptor, You can use softer balsa than on the E version. That will make it easier to sand them down to the nice, rounded look I used; just be sure to sand them to shape, THEN glue onto the wings and vertical stabilizers. That way, when you seal and sand, they become 'one' with the surfaces. Also, it's easier to sand your leading and trailing edges more uniformly to include the reinforcements. I mainly did that because the decals lie over them so much more nicely than they would over the style suggested in the E instructions. Good Luck! Happy to help if I can! :D
By the way, I prefer to do all the wing and rudder assembling and sealing and sanding BEFORE they go on the rocket. Much, much easier to accomplish. You can prime everything after they are all glued on. Use epoxy: I use 5 min epoxy to attach the fins and use 30 min for the fillets. Wet your fingers with alcohol to make that easier, too. You can do the whole thing in a day. ;)
Allen

Mikus
06-05-2008, 06:18 PM
I used card stock and 3M spray. You're going to end up with a seam since one sheet (8.5X11) won't cover the entire fin. If you can get 8.5 X 14 or 11 X 17, you can get it seamless. I didn't trim the card stock until after it was applied to the fin so I didn't have to worry about getting it just right.

I was planning on contact paper for mine. :D

ga1ba2
06-06-2008, 06:28 PM
If anyone was courious about Hobilinc's replacement time I received the replacement fins today. Took about 3 days after notification :)