SCRAPPY-55 Build Thread

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Woody's Workshop

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I'm using scrap pieces of balsa that were in shape of the fins. It must have come from waste from a larger kit.
The Air Frame is BT-55 11-7/8" long which is salvaged from a scratch build that got ruined in the quick move out from the Fire back at the end of March.
The 18mm Engine Mount is also a salvage part from another scratch build that also got ruined in the quick move out.
The Launch Lug is a 1/8", 3" long previously mounted on Air Frame. Not the best location or length, but it is getting used and it will fly according to RocSim.
I have previously papered the fins, marked and cut for the mounting tabs at 1/4" (from a scrap piece of cut off from my previous wood shop I saved, comes in handy) and 45 degree cut the front ends, and flat cut the aft ends as they will be flush with the bottom of the air frame.
It's going to be a real challenge to work the fillets in the launch lug fillets, especially since that tube was previously done in TiteBond II, and is several years old.
A fair amount of water soaking will have to be done to soften up the old glue so the new glue will bite in good. Also, when sanding the new glue if it doesn't bite in good, it won't feather. The new glue will roll up and pull off the air frame when sanding.
Here is the design (Color is not accurate) and few of the first few pics.
I'll do this one as I go and not wait until the end like the Quest Courier and Estes Alpha Butild Theards I'll be doing.
Enjoy.
 

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This morning...er...afternoon I guess it is already...
I took the Scrappy-55 out of the fin jig and checked the fin alignment.
Looks good.
I gave the first of 4 coats of TiteBond III to 1 side of 2 fins and covered the paper tabs.
A couple of pieces of 2x4 held together with rubber bands makes a good stand for many things.
I use smaller 1x3's on smaller rockets, and even 1x1.5 for the tiny ones.
 

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And...the second coat of TiteBond III is on those same sides of the 2 different fins.
Couple hours of dry time, until the glue dry's enough to change color.
Dry to the touch, yet can't be bruised and soft enough for the next coat to bite in real well.
 

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Thanks for posting this Woody. I’ve been curious about your “Titebond as filler/sealer” approach since you first mentioned it.
 
And...the forth coat of TiteBond III on one side of 2 fins AND the first fillets are in place.
It will a bit longer for the fillets to set up, so maybe tonight I can get the second coat of fillets on.
 

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The glue hadn't set up enough by the time I went to bed last night.
Here is the 2nd coat of TiteBond III for the fillets.
After this coat sets up I'll give it one more coat and then smooth it out with a paddle to get the shape I want.
Doing 2 filler coats first helps fill in the deepest area as the glue does shrinks when it drys.
 

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Had to wait until this morning to put the final coat on the fillets and paddle them out.
I'll skip the rest of the fins being coating and the fillets. No use in duplicating here, what has already been showed.
I'll pick up when the sanding starts.
 

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So Woody how did you learn this technique ? My first tutorials in model rocket construction were the beyond excellent Estes kit instructions from the late ‘60s and Mr Stine’s Handbook. I don’t recall either mentioning this use for glue.
 
It came about through a process of trying different things to get a better finish, while improving the strength of the components.
I use to use wood filler, but that wasn't getting the job done on balsa.
I had several fins break on landings, even after I started gluing them.
So I improved on the papering fins technique as showed on Apogee's web site.
I was an auto body tech for 17 years, so a good straight finish was important.
And being a wood worker, I had a little better understanding of how glue works.
I experimented with different things like thinning glue about 75% with water for the first few coats on balsa nose cones.
It has worked out pretty good so far. I haven't had any damage to nose cones and it takes quite a wack to get a dent.
I noticed after several flights the inside of the air frame would get scorched, so I started coating the inside of the air frame as well.
It not only protected it from getting scorched, but on hard landings I got a considerable less amount of kinked air frames.
So it's an added layer of strength.
Yes, it adds weight. There is always a give and take.
 
I ran out of batteries, so haven't been able to update lately.
Had a terrible time with the BT.
I'm guessing because that particular BT was left in the apartment during the fire until the next day, it must have absorbed a lot of moisture that was in the building.
Basically, the glassine fell off, and had to start all over.
When I was sanding the Fillets, a fin popped off.
Tried the other 2 and they popped right off, along with the launch lug that had been on there for a few years.
Used it as a trial and error project for saving a BT.
Just finishing it back up now, and only have a launch lug to add back on.
I'll get some pics up as soon as I get some batteries for the camera...
 
Scrappy turned into a trial and error project to save a BT.
After spending hours upon hours putting glue on and sanding it down...
I just cut the BT off just above the fins.
I'll be adding a new piece of BT-55 to finish the project.
Still no batteries for the camera, so pics will come when I can get some batteries...
 
The Scrappy project has turned into scrap.
Fins have been removed, with fillets and mounting tabs.
Engine Mount was cleaned up.
I'm pretty sure that trying to salvage the BT that had drawn moisture from the fire was it's demise.
I'll put it back together with a NEW piece of BT.
Since we are returning to strict budget again to move into a ground floor 3 bedroom apartment...
I am not sure if batteries for the camera are in the near future...
 
Since I started with a new piece of BT, I made it an even 12" long.
For the heck of it, I did a sim putting a D size Engine Mount in it.
Stability went to below 1, but altitude was just under 1700 feet.
I'll keep the RocSim on the D, but building it for A-C engines.
That is...Until I find a field large enough to fly it on a D.
Then...I build one of those also!
 
Woody is there something unique about TiteBond III for this, or can I used regular wood glue or white glue?
Are you using this straight or watering it down?
 
I've tried over a dozen glues. TiteBond III sets up quick, and can be sanded quicker. It's less gummy.
I think one of the reason's for this, is if you look on TiteBond's web site you see tensile (I think) strength and III's got the highest.
But things like high humidity days will greatly extend dry time.
Diluting it depends on what your doing with the glue.
Shoot me an Email at [email protected] and give me your specifics, and I would be more than happy to give advice.
 
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