Binder Design Velociraptor Rebuild Thread

Sooooo… Way back in June, I attended Southern Thunder. While there, a charity auction was held. I bid on, and won, an assembled Binder Design Velociraptor for $15.00. The rocket is in rough, but acceptable, shape. The paint wasn't applied with much care or finesse for edges.

The A/V bay has a large hole from an electric key switch that I assume armed the electronics. There's also a small split on the second airframe tube and a crinkle on the upper airframe edge.

The booster airframe has a wrinkle just below the central fun that will need to be addressed. Also the tail cone seam at the booster is not filled.

The fins were not very well finished at the edges or the flats. The sharp edge was just knocked off and the fin was painted.


This is going to be a pretty detailed rebuild. Since I can't easily disassemble the booster, the work will be even harder to perform.

I've already ordered and received the parts for a new A/V bay. Cost me $19.50 shipped for the parts. I'll still need to order replacement decals, but that can wait till its done. Plus, I may need to have mine custom made. The colors I want to use are not available from Binder Design.

Can't argue with $15, but yeah, needs some work...

I've started by removing the existing decals. They all came off decently. Obviously they weren't clear coated. They did leave a rather significant layer of adhesive behind. I'll remove it before sanding. I don't want it clogging my sandpaper or causing uneven sanding.

I'll be using a light mineral spirits to remove it before sanding. I'll use light motions and several applications to remove it. I don't want to chance getting too much moisture in the wood.

Kruegon said:

I've started by removing the existing decals. They all came off decently. Obviously they weren't clear coated. They did leave a rather significant layer of adhesive behind. I'll remove it before sanding. I don't want it clogging my sandpaper or causing uneven sanding.

I'll be using a light mineral spirits to remove it before sanding. I'll use light motions and several applications to remove it. I don't want to chance getting too much moisture in the wood.

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With all that damage, I wonder if it would be a better idea to try to tear it down to the centering rings and motor tube, and completely replace the body tubes and couplers (as necessary). As is, I'd be worried that the buckles you mentioned would compromise the airframe if it was given a motor with some serious kick to it.

Well, I've addressed similar on rockets before. The crinkle in the booster will be sanded, removing the buckled outer layer. A thinned layer of 30 min epoxy will be applied and later sanded. The layer of epoxy will actually be stronger than the original tube.

The small tear will be cleaned and trimmed before applying epoxy to that area. Then it will be layered with wax paper and pressed by clamps on semi-rigid curved plates. Then sanded back to proper thickness.

The slightly crinkled edge will be straightened. Then I will perform a CA soak of the tube inside, along the edge, and covering a small area over and just around the crinkle. Then sanded back to thickness as the other was.

Once finished, the strength will be superior to the original tube. The key is ensuring the areas are properly penetrated with the adhesives. Time consuming, but actually the easier option. I'll be posting as each step is completed so that the repairs can be seen. Then after prep and prime, we'll compare them again.

Kruegon said:

Once finished, the strength will be superior to the original tube. The key is ensuring the areas are properly penetrated with the adhesives.

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I agree. Any creases or wrinkles can be fixed by cutting out a section of glassine and soaking in thin CA and sanding smooth, spot putty and paint. Let me know what color of vinyl you need for decals.

Just a quick update. The fillets were not very even. I'm in the process of removing them before sanding for repairs and paint. There are 9 fins so it's a slow process. I have one fun left then I'll post a pic of the cleaned edge.

One thing I noticed is that the epoxy fillets on the tail fins did not bond well at all to the plastic tail cone. Any suggestions for a better bonding method here, I'd hate to get it painted and have a release of the adhesive weaken the fin and crack the paint.

I don't know how well it will hold a fillet shape, but I have had success with the Loctite Plastic Epoxy. Cures nice and solid on nosecones.

That's a really good looking design, it's no mystery why it "inspired" others to market the split fin design. Good luck on your rebuild!

Kruegon said:

One thing I noticed is that the epoxy fillets on the tail fins did not bond well at all to the plastic tail cone. Any suggestions for a better bonding method here, I'd hate to get it painted and have a release of the adhesive weaken the fin and crack the paint.

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A couple ways to do his.

Carefully rough-sand the section of plastic and the fin root to be epoxied with 40-grit sandpaper and roughen it up real well. I find that the rough sand cylinders for Dremmels makes an extremely coarse surface and you are able to control where you sand very well. Run the Dremmel at about 1/3 speed and lightly touch the surface, Otherwise you can gouge it real easily Then use RocketPoxy which has a very long curing time to bond together.

You can also drill 1/16" - 1/32" holes about an inch apart in the plastic next to the finroot at a angle into the fin root to allow the epoxy to seep through the holes and into the fin root. Be careful not to drill through the fins so that you create tiny cups instead of a channel for the epoxy to leak through. Otherwise your completed fillets will have dimples. This combined with rough sanding should help you build an excellent bond.

RocketPoxy makes excellent fillets, but you can only do two fillets (or sets of fillets) at a time, and allow at least 4 hours for them to cure. Tape up the areas that you do not want the epoxy to touch. Lay the airframe across something like an open vise that can keep the airframe level. Turn it so that a pair of fins oppose each other at with chord edges at the same height above the floor. Apply the epoxy. After it is applied to your liking, immediately remove the tape. If you remove he tape at this point, you will have much less of a lip where the tape line was because the epoxy has a tendency to settle and level out. Then let it set until completely hardened.

Even an hour or two later, if you turn too early, the epoxy will have a tendency to run (very slowly, so you think it will be OK...even after 5 minutes...but a half-hour later you will be cussing). Once cured, turn the airframe and repeat the process. It may take you the whole weekend on this rocket, but your fillets will be awesome.

Heating the epoxy mix with a blowdryer before you apply it will make the mix thinner for about 5 minutes, but then it will cure faster. Doing this also releases more air bubbles. If in the first 20-30 minutes you see air bubbles, poke the bubble with a toothpick, then leave it alone. You will initially have a hole about 1/16" wide, but the epoxy will slowly fill it in then level out on its own.

Make sure and thoroughly clean the edges to be filleted with alcohol to remove any oils or crud left from the molding process (if it wasn't cleaned well enough originally), or just to remove the sanding/roughing up dust. I like to drill 1/16" holes under the fillet on plastic boattails and wipe the epoxy into them to create epoxy rivets, the plastic epoxy recommended might be the best product for the initial fin to boattail bond.

Quick update. This is not a dead thread. Just taking my time and doing it right. The next update will be in a few days.

Ok I got a bit more accomplished on the rebuild. All of the old fillets are gone. Took a good bit of time to cut these out cleanly. I'm very lucky that the original builder used a moderately soft epoxy.




I also managed to get the two upper body tubes sanded. This took a lot more time than I ever expected. I used 120 grit sandpaper and went through four pieces getting them clean. There was a primer, a coat of blue, and the black. I can only assume this rocket has been painted at least twice. I suspect I'll find areas of four layers on the booster section.

I also filled the spirals on the new switch band and cut down the new couplers. The original a/v bay was 12" long. The new parts had two couplers 7" long each. While that wasn't an issue, the existing all thread was cut for 12". So I removed 1" from each coupler.



I also started working on the small split in one of the upper body tubes. It wasn't bad, but when I get ready for paint, I don't want any issues. It's been filled with BSI 30 min epoxy and lightly clamped. I'm just waiting for the epoxy to finish curing fully, then I can sand and shape the edge.



I'm hoping to be able to sand the booster tomorrow. I'm not looking forward to the fin work. But if I want it to look good, I need to work on every aspect equally.

I don't envy the work you've got yourself into, but I do envy you for having:

I certainly lucked up on the Velociraptor. I couldn't even begin to afford the kit right now.

What's preventing you from working on a rocket? I hope nothing's wrong.

Kruegon said:

I certainly lucked up on the Velociraptor. I couldn't even begin to afford the kit right now.

What's preventing you from working on a rocket? I hope nothing's wrong.

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I'm living on less than $600USD/¥3888RMB until my first paycheck (Feb 1). I don't know what surprises China has in store for me until then, so I don't dare send for any rockets. Also, I have zero idea how much it will cost to ship them here (they weren't the smallest boxes in the world).

Besides that, I have no clue where to find (nor the ability really to ask for):


I've finally started making contacts with other foreign teachers here, so my knowledge base is improving.

I wish you luck. How long will you be staying there?

Kruegon said:

I wish you luck. How long will you be staying there?

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Dunno... My contract is for a year, I might extend it to two, then I'll be trying to head to TW to teach and further my education.

Did some work on the small tear in the body tube. I laid it up with 30 min BSI epoxy yesterday. I went a little thick on it. That gave me some room to shape it. Using a palm sander, I shaped the basic curve. Then I hand sanded it for final feel. I'm satisfied with the exterior. I still need to sand and shape the interior.



After cleaning it up, I went ahead and primed the tube. It's currently drying. The vigorous effort to remove so many layers of paint took its toll. In many places I actually burned through the glassine. This naturally left a lot of hairy paper fibers standing out. The priming, and subsequent sanding, should allow me to smooth the surface back out and make a base prime surface to begin the rework on any remaining spirals and begin painting.

Quick update. Weather is cold. Painting is a pain. It's taking forever for primer to dry. I did manage to slick the first body tube. There were some surface imperfection that went beyond primer's ability to fill. I filled these spots and sanded them, as well as sanding the primer again. Each time I feel the tube is close to ready, I'm priming it to ensure I locate the imperfections. But I'm also being sure to keep it thin and remove the vast majority during sanding. I don't really want 5+ full coats of primer on here. Paint gets heavy.

I filled and sanded the new switchband. I added a coat of primer and found that it's not nearly as ready as expected.

I did the same with the second body tube. It's also quite fuzzy and will require the same steps the first one did.

Just resurfacing the tubes is turning out to be a build's worth of work. But I'm really hoping the finished product will meet the same standards as one of my fresh build's.

Once these tubes are ready, I'll be sanding the booster section and working to strip the paint on the nose cone and tail cone. I picked up a gallon of simple green for this. Any suggestions on the best way to use this product to remove paint from such a long nose cone? This thing is like 16.25" long plus the shoulder.

Life can get interesting when you rebuild a rocket built by someone else. Sanding the tubes until you burn through the glassine doesn't help.

This is primed and light sanded. I used wood filler the same way we fill spirals to fill and level the rough and low spot created by the harsh sanding. This the result:



The same thing occurred with the first tube I worked on for this rocket. The first tube has been sanded to bare, primed to find the bad spots, sanded smooth, filled with wood filler, sanded smooth (again), primed again, sanded smooth (yet again), and currently has the final wood filler touch up (hopefully) on it now.

The weather is cold and moderately humid so drying times are around 24 hours between sanding. So roughly 48 hours from now I can, hopefully, display the final pre-primed tube.

Once the entire rocket is at the same stage, it will receive a nice, even coat of primer to ensure it is ready to be painted. Cross your fingers. The road ahead is still long.

When tubes are down to the paper like that I just brush on some sanding sealer to soak into the paper and sand smooth then primer.

I've tried that before. The finish turned out decent and workable. The problem I had was the shear amount of sealer the roughed paper soaked up. Enough to make it noticeably heavier. Of course it was Estes BT-80. Lighter tube probably helped the weight feel noticeable.

The last major steps on these tubes will be the edge reinforcement and the internal finish of the torn tube area.

I put the nose cone into a bath of Simple Green tonight. I'm hoping to see noticeable results in 24 hours. Does anyone have a comparison for how long you'd expect it to take to strip the paint?

Kruegon said:

I've tried that before. The finish turned out decent and workable. The problem I had was the shear amount of sealer the roughed paper soaked up. Enough to make it noticeably heavier.

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Totally worth it. It will soak up a lot of primer too. No getting around that. Lately I've been soaking the whole insides of the tubes after the rocket is built. It seals the paper and makes the tube noticeable stronger and more durable. I've used lacquer based and water based. You don't want the lacquer. It dries a bit faster but you need lacquer thinner to clean the brush and your tubes "off gas" for a month. Water based is a bit more expensive but worth it. easy clean up and no stink.

For stripping paint off the cone, a random orbital sander does wonders. Super quick and leaves a nice surface for primer.

Binder Design said:

When tubes are down to the paper like that I just brush on some sanding sealer to soak into the paper and sand smooth then primer.

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Binder Design said:

Lately I've been soaking the whole insides of the tubes after the rocket is built. It seals the paper and makes the tube noticeable stronger and more durable.

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Ok, you've got me curious here Mike... What brand of sanding sealer do you use/recommend.

K'Tesh said:

Ok, you've got me curious here Mike... What brand of sanding sealer do you use/recommend.

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Minwax. https://www.lowes.com/pd_162054-678-657000000___?productId=999914203&pl=1&Ntt=sanding+sealer

Been soaking my couplers in it too.

Binder Design said:

For stripping paint off the cone, a random orbital sander does wonders. Super quick and leaves a nice surface for primer.

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The only issue I had trying that is that the nose cone is a tiny bit small for the tube to begin with. Didn't want to reduce it farther. Not even by a little. I'm actually thinking of adding bindi to the cone to make it match the tubing better. I'm adding a layer of epoxy inside the tube to make the shoulder fit better.

Thanks K'Tesh and Mike. I was staring at Minwax sanding sealer the other day at Home Depot. So much cheaper than Aerogloss. I just went through half of a bottle of Aerogloss on my Tyrannosaur last night.

Binder Design said:

Been soaking my couplers in it too.

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That may not be a bad idea. I've been soaking the edges of my BTs and couplers with CA to prevent ruffles and tears. I wonder. If I were to soak and slick sand the exterior of the coupler, would it assist the coupler with insertion and removal? The BD couplers have a really close tolerance.

Trying not to derail this thread, but Mike has me curious as well regarding 'soaking' the insides of tubes with sanding sealer. How exactly do you do that? Paint brush on a stick?