First build as a BAR: Estes Solar Warrior, #3225

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neil_w

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Not counting a pair of E2X models I recently built with my daughter, this will be my first real build since the 70's. I like the Solar Warrior design a lot, and it seems just about right for my return to the hobby. I haven't seen much written about it so far, so I presume it's a fairly recent kit.

I'll be following a lot of Chris Michielssen's techniques because they're so darn well documented.

This is of course my first ever build thread as well. I'm hoping it will motivate me to keep things moving and get this done in a reasonable amount of time. So tune in to see my middle-aged wisdom and experience fight it out with my rustiness and unfamiliarity with new techniques (in other words: watch me screw up and try to deal with it).

Onward. Here are the parts:

solar_warrior_parts.jpg
 
First some basic parts prep. I needed to separate the nose cone from the exhaust nozzle, and remove the plastic cap on either end of the nozzle. Time for my first mistake (that didn't take long, did it): I started with the one cut that would be visible in the finished model, the cap at the business end of the exhaust nozzle. Lacking a proper saw, I thought a box cutter with fresh blade might do the job. The blade angle made this a bad choice. I struggled a bit but got the cut done, then went on to mistake #2: trying to carve out some of the bulk of the extra material with the same stupid blade, so I'd have less to sand. It was very hard to control the blade so I ended up nicking the edge of the nozzle. I immediately abandoned this approach, and finished it with sanding. It's not a disaster, and once painted black won't really be noticeable, but lesson learned. After that, I did my cuts with a #19 Xacto blade, holding the knife parallel to the bench while rotating the nosecone, and doing all finishing with sanding. This worked much better. Final result (you can see the overly deep cut on the top left):
nozzle.jpg

The nose cone went without incident. I sanded down the molding seam, but I haven't decided whether I will need to apply some filler to achieve ultimate smoothness. It's not bad, and to maintain my sanity I'll probably skip the filler for this build, unless I get ambitious later.

Next I began my first adventure with CWF by doing the body tube (this is a step I had never heard of back when I was a kid). This actually went quite well; I applied with a chopstick and squeegeed with an old dull box cutter blade converted to a safety razor (sort of) with the application of some foil tape on the top. The CWF stayed in the seam while sanding, which made me happy. I think it came out OK, although I can't tell if I sanded down far enough, but it *feels* smooth. We'll see how it goes when I paint.
bt_1.jpg

So far so good with the CWF.
 
Each fin has four pieces, and there four canards as well. I cut everything out from the laser-cut sheet and immediately encountered a problem: one of the grains in the balsa was almost completely split, cutting two of the main fins almost in half. I decided that the best way to really fix them was to finish the job of breaking them apart at the splits, and then gluing them together with a double glue joint. This seemed to go OK, and so I rounded the leading and trailing edges and assembled the compound fins:
View attachment 269262

Once dry, I added another layer of titebond II to the seems, both to fill the cracks and make it stronger. I am wondering if I should have tried to just strengthen them with CA or something like that and avoid breaking them, but the end result seems to be OK.

And now the real fun begins: CWF on all the balsa. After my first coat (on both sides!), my carefully repaired and assembled compound fins looked like this :y::
doritos.jpg

These are 3/32" thick, BTW. Thus began a sequence of wetting and pressing the fins to get them flat again. They are in the press as I type this; I took a peek this morning and I *think* they look pretty flat now, finally.

The smaller pieces at the top of the picture will be laminated together to form the, uh, perpendicular pieces at the end of the fins (is there a proper name for those?) Because I didn't know how the wood was going to behave, I decided to CWF them first, on both side, and then glue. In hindsight, they were small enough that they had no warpage issues, so I could have easily glued them first and then just CWFed the exposed sides and saved myself some work.
 
Dunno if anyone is following this thread, but I will soldier on.

After leaving the fins in the press for a full day, they finally came out looking flat, or at least about 99% flat. To the remaining 1% I say "oh well".

fins-post-pressing.jpg
I learned from my previous experience and sanded the CWF much more efficiently this time, quickly taking off the heavy layer with 220 grit, and then using 400 to finish. Ran into another problem with one of the fins; while sanding the trailing edge with the 400 grit, a small piece came right off the corner and floated down in the abyss of my CWF dust-filled garbage can. Bye bye. So I cut a small new piece, glued it in, and sanded it into shape. Pictures below show before and after. The finished fin is now five pieces vs. the intended two (I didn't mention that the leading edge part of the compound fin originally came in two pieces; that was my first fin repair.) I think it'll look fine once painted, and all the joints (Titebond 2 double-glue joints + extra applied like a fillet afterwards) seem very very strong.
problem_child.jpgproblem_child_finished.jpg

If you're wondering: No, I didn't bother CWFing that little corner piece. I'll live with that.

Attaching the perpendicular pieces to the ends of the fins was uneventful. After gluing them on as specified in the instructions, I applies one layer of fillet so I am calling them finished. Here they are, sitting upside down.
finished_fins.jpg

They're a bit ugly right now with all the extra glue seams, but I think once assembled and painted they will look good.

I think I'm going to prime them in this position (after masking root edges), and then hit the other unexposed ends with one quick shot of primer after the rest dries and I can lean them on their sides.

If I had to start over, I think I could get the fins ready in about half the time this took, or less. We'll see if that's true when I do my next build, whenever that is.
 
Dunno if anyone is following this thread, but I will soldier on....


Yes, please do, didn't know if you wanted alot interruptions mid-build. One thing I use to sand the filled spiral is an emory board:

emory board.jpg

I try to remove all of the filler outside of the spiral groove without abrading the glassine layer on the rest of the tube.
 
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I also purchased this one during the sale. I will be watching your thread very closely for when I do mine.
 
Keep it up, I got two of these from Tower's big sale that are waiting to be built. It's a sharp-looking sport kit.
 
Thanks for the encouragement. Feels a bit less lonely in here now. :) If anyone wants any more pictures or more detail on anything, let me know. I'm making it up as I go along here.

Yes, please do, didn't know if you wanted alot interruptions mid-build.

Are there people who don't want interruptions in their build threads? :confused: That honestly never occurred to me.

One thing I use to sand the filled spiral is an emory board

Ah, I forgot about those, just picked up a couple of the soft ones (280 and 320 grit) at Target. I think I'll have a better time with the soft ones than the hard ones, but we'll see when I try them out.

What I did for the spirals was to take a strip of 400 grit sandpaper, about 3/4" wide, and sort of conform it to the spiral, and just work it down the tube, following the spiral. The seemed to work OK, but I'll find out when I prime if I left too much on the tube (did you have any opinions based on my previous picture?)
 
Thanks for the encouragement. Feels a bit less lonely in here now. :) If anyone wants any more pictures or more detail on anything, let me know. I'm making it up as I go along here.



Are there people who don't want interruptions in their build threads? :confused: That honestly never occurred to me.



Ah, I forgot about those, just picked up a couple of the soft ones (280 and 320 grit) at Target. I think I'll have a better time with the soft ones than the hard ones, but we'll see when I try them out.

What I did for the spirals was to take a strip of 400 grit sandpaper, about 3/4" wide, and sort of conform it to the spiral, and just work it down the tube, following the spiral. The seemed to work OK, but I'll find out when I prime if I left too much on the tube (did you have any opinions based on my previous picture?)

My opinion is that from here it looks like you could take a little more off with some localized light sanding. But I use my fingers at this point as well to get an idea when to stop sanding. Of course, all that said, the first primer coat can be a little shocking when I see all sanding fuzzies and filler voids that I missed. :) Looks like your right on track to me.
 
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Time to prime. I'm really into unknown territory here; I can't for the life of me remember how I used to do priming, but it sure wasn't like this. I've elected to try the Rusto Filler/Primer because it's half the price of the Duplicolor, and some have posted on this forum of having good luck with it.

First I CAed both ends of the tube, because I was about to start handling it a lot and it seemed like a good time.
CA_tube.jpg

I am hilariously inefficient at preparing everything for priming, and improvised a fairly ridiculous holder for the body tube using PVC pipe and fittings I have lying around (it looks better in the picture than it really was, I promise). The nose cone was masked on the shoulder and inserted 3/4 the way into the tube.
tube_ready.jpg

As with everything in this build, I have some ideas how to do it better next time.

The fins are all arranged on tape, and I fashioned an Amazon box into a quasi-painting booth (spraying to take place outside):
fins_ready.jpg

I found the primer pretty easy to apply, although I had no idea if I was applying enough, or too much. A few hours later, I dry-sanded the body tube, nose cone, and nozzle with 400 grit and it went well, although (predictably) it really gunked up the sandpaper quickly. That may be the one reason I try Duplicolor in the future, to see if it gunks up less. Anyway, here are the results of the tube and nose cone:
finshed_tube_and_cone.jpg

I seem to have left more primer on than hcmbanjo normally does, but it feels fantastic and I'm inclined to think I'm in good shape here. No spirals visible and very smooth.

The fins are going to be more troublesome, for a number of reasons.I haven't sanded them yet, will report back when I do.
 
You're doing a great job so far! I might have to get myself one of these kits.
 
JUST built one of these as well. Waiting for a small amount of glue to dry in the nosecose for some clay I added so I can use this rocket with the AT Economax motors. I'll post a pic later tonight on the finished kit. It looks like it'll be a good flyer.
 
Here's mine... sorry for the delay. Wanted to make sure the glue in the nosecone was nice and dry before putting it in the vertical position on the rocket. :)
CIMG4340.jpg
 
Spiffy! I like the gradient between the purple and white. The canards look good down there by the fins as well.

I'm planning to do purple on top also, although keeping the rest of the design stock.
 
Finished sanding all the primer tonight. The fins were not as much trouble as I feared, although it took a bit of care to sand in all the nooks and crannies. Truly, finish-sanding is without doubt my least favorite part of this hobby. But I think it all came out OK.

Upon close inspection, I decided that the body tube needed more sanding, so I took off a bit more primer and got rid of some not-quite-smooth spots.

Here are the results:
finished_primer.jpg

Next up is probably the motor mount, some nice simple gluing and cutting with no sanding. :)

Oh, I picked up some coast lock snap swivels today at Dick's; never used them in the past but they sure seem like a good idea.
snap_swivel.jpg
 
Spiffy! I like the gradient between the purple and white. The canards look good down there by the fins as well.

I'm planning to do purple on top also, although keeping the rest of the design stock.

Thanks... the photos don't do the purple justice, it's actually an odd deep blue. And yes, I liked the look with the canards down lower. :) I'll let you know how she flies next week. D12-5 to start, then E9-6. Hoping for no E9-6 CATOs like last launch!
 
Well that was refreshingly straightforward and free of sanding. Motor mount was pretty standard stuff, although the ring inside the mount just above the engine hook was a new one to me (this is my first D engine model), and getting it to sit straight in the tube was a bit tricky.

The illustration in the instructions was a bit ambiguous regarding the sleeve that fits over the hook. It shows the sleeve just below the point where the hook inserts into the tube, then another picture shows it all the way flush with the aft centering ring. I concluded it made more sense that it should be up by the entry point.
motor_mount.jpg

I have not yet decided whether to do a kevlar shock cord (or a kevlar mount for an elastic shock cord), so I made a hole in the front centering ring just to keep my options open.
kevlar_hole.jpg

One thing I learned here is that the Titebond is quite sticky, and I'm really making a mess when trying to lay fillets. I'm going to have to be careful when I do the fins so I don't end up with glue all over my carefully CWFed and primed surfaces. Do people mask their fillets? My impression is that that is just for epoxy. I'm also considering getting some of the mold and trim glue, since some seem to like that for fillets.
 
Well that was refreshingly straightforward and free of sanding. Motor mount was pretty standard stuff, although the ring inside the mount just above the engine hook was a new one to me (this is my first D engine model), and getting it to sit straight in the tube was a bit tricky.

The illustration in the instructions was a bit ambiguous regarding the sleeve that fits over the hook. It shows the sleeve just below the point where the hook inserts into the tube, then another picture shows it all the way flush with the aft centering ring. I concluded it made more sense that it should be up by the entry point.
View attachment 269678

I have not yet decided whether to do a kevlar shock cord (or a kevlar mount for an elastic shock cord), so I made a hole in the front centering ring just to keep my options open.
View attachment 269677

One thing I learned here is that the Titebond is quite sticky, and I'm really making a mess when trying to lay fillets. I'm going to have to be careful when I do the fins so I don't end up with glue all over my carefully CWFed and primed surfaces. Do people mask their fillets? My impression is that that is just for epoxy. I'm also considering getting some of the mold and trim glue, since some seem to like that for fillets.

I used the molding and trim for my fillets, it works well. I also "straightened" the engine hook and wrapped it with the wife's old panty hose and soaked in glue in addition to the ring to allow for 24mm x 95 mm engines and just put the motor block in at the end of the tube.
 
Ok Neil, you've got yourself a problem. Glue doesn't like to stick to paint. It will, but it's a *LOT* weaker. Priming the body tube before gluing on the fins seriously compromises the bonds. If you want to continue with this body tube, you need to expose the body tube for the glue to achieve the best glue joint (as well as removing any paint you may have got on the fin's root edge (I see you masked the root edge, but JIC))

If you don't, you'll very likely find yourself with a rocket that sheds its fins on launch, landing, or just in routine handling. You'll constantly be gluing the fins back on, unless they are TTW (Thru The Wall)(and a stock Solar Warrior doesn't use TTW), but again when it comes to fillets, you've got the problem of how the glue will adhere to the paint.

If you haven't already glued in the motor mount, I'd recommend setting this body tube aside, and buying some more body tubes for a reboot. Don't worry, you can use this tube for something longer with a separate piece for the fin can (think Vagabond). I've bought body tubes from MoreRockets.com, and 10 BT-60 body tubes that are 22" long for $8.49 is a STEAL. Presuming you go this route, you should seriously consider buying the ESTES Tube Cutting Guides to cut your new body tube down to length.

Presuming that you glued in the MMT, I'd recommend that (using the Estes Tube Cutting Guide) you cut off the end of the body tube with the mount (save the remainder for a later build). Then you can salvage the MMT by peeling the body tube off of it, and glue it into a new tube.
 
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K'Tesh,
Thanks for the input. The root edges of the fins were masked and are clean, and I do plan to remove the primer from the tube before gluing (that'll actually be my next step). If it doesn't go well then I can certainly replace the BT if necessary (motor mount is not in yet, I'm gonna do that last), but I'm hoping I can get it to work. I will certainly not glue to the primer under any circumstance.

If this technique doesn't work out for me, then I'll do something different next time. I'm still getting a feel for its pluses and minuses (if the fins come off then that would definitely be a big minus. :))

Thanks for the Payload Bay link, I hadn't seen that before and it looks great.
 
Ok Neil, you've got yourself a problem. Glue doesn't like to stick to paint. It will, but it's a *LOT* weaker. Priming the body tube before gluing on the fins seriously compromises the bonds. If you want to continue with this body tube, you need to expose the body tube for the glue to achieve the best glue joint (as well as removing any paint you may have got on the fin's root edge (I see you masked the root edge, but JIC))

If you don't, you'll very likely find yourself with a rocket that sheds its fins on launch, landing, or just in routine handling. You'll constantly be gluing the fins back on, unless they are TTW (Thru The Wall)(and a stock Solar Warrior doesn't use TTW), but again when it comes to fillets, you've got the problem of how the glue will adhere to the paint.

If you haven't already glued in the motor mount, I'd recommend setting this body tube aside, and buying some more body tubes for a reboot. Don't worry, you can use this tube for something longer with a separate piece for the fin can (think Vagabond). I've bought body tubes from MoreRockets.com, and 10 BT-60 body tubes that are 22" long for $8.49 is a STEAL. Presuming you go this route, you should seriously consider buying the ESTES Tube Cutting Guides to cut your new body tube down to length.

Presuming that you glued in the MMT, I'd recommend that (using the Estes Tube Cutting Guide) you cut off the end of the body tube with the mount (save the remainder for a later build). Then you can salvage the MMT by peeling the body tube off of it, and glue it into a new tube.

K'Tesh is right! Glue won't stick to a sealed, primed paint.
You mentioned earlier that you didn't sand off as much primer/filler as I usually do, shown in pictures on the blog.
I use primer/filler to fill any remaining seams on the body tube.

In many blog posts I sand a strip down to the body tube where the fins and fillets will go.
The sanded strip is wider than the root edge of the fins and wide enough that the fillets will just cover the rough sanded strip.

The Rusto filler primer doesn't sand off as easily as the Duplicolor filler primer (FP101)
The Rusto is rubbery and loads sandpaper very quickly. You didn't sand it down far enough.
There are reasons why my sanded filler primer is taken down so far before the fins and lug are glued on.
It helps for a stronger fin and lug adhesion.
 
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Thanks, I will try to clear the fin and lug attachment areas as thoroughly as possible before attaching the fins. Maybe I've made extra work for myself but I feel like I ought to be able to get it into good shape eventually. If not.... well, it'll fall apart and I will have learned. :)

In the future I might also try masking the fin attachment areas before priming.

I will also probably try the Duplicolor next time to see if it sands better. I did not enjoy sanding the Rusto primer but I wanted to try before giving up on it.
 
I cleared away the primer from the glue areas, went very well although I got a little sloppy and roughed up more of the tube than I wanted to. Will apply a little more primer and that should do it.

One thing I learned: my 220 grit sandpaper has no problem with the Rusto primer, takes it off effortlessly and doesn't seem to clog as reaily. Something I'm going to consider in the future is to start with the 220 and use it very gently to take off the heavy primer layer, and then switch to 400 to finish. I'll also experiment with some 320 (which I don't have at the moment), to see if it behaves more like the 220 or the 400 with regards to the primer.

Pictures and more details tonight.
 
After sanding the BT down further, and then removing almost all the primer from the fin and lug attachment areas, I masked those areas on the tube to prepare for on more quick shot of primer to smooth out the areas I scuffed by accident:
body_masked.jpg

For each fin I removed the primer in the fillet area (the root edges were already clean). Here's what one looks like:
fin_fillet_ready.jpg

Once I re-sand the body I'll be ready to start gluing everything together (finally).

For all the mistakes and redos I'm still pretty confident this will come out well. The next one will be quicker. :eyepop:
 
And so the world's most drawn out skill level 2 build continues.

Desperate to glue *something*, I attached the lug. That went fine, and I built some fillets with Titebond M&T, which looked great but they did develop a couple of small bubbles. I might add one more fillet layer over it just for cosmetics; it's definitely very strong.
IMG_2984.jpg

I decided to sand some more primer off the fins, using my new two-stage process (take off the heavy layer with 220, then sand smooth with 400). This worked so much better, and more quickly. Here are a couple of the fins now *really* ready to go:
FullSizeRender 2.jpg

What has caused me no end of trouble has been the warped fins. Although I finally got them *almost* straight, there is still a slight bend in a couple of them that makes sanding with a block impractical. So I've had to be very careful with them.
I really wanted to try to straighten them out when attaching to the body, so I had a great idea and strapped two pieces of aluminum angle to the body, exactly surrounding the fin mount points:
FullSizeRender.jpg

It's a little hard to see in the picture. With the angles positioned correctly, they *will* force the fins to be straight at their attachment points. Unfortunately, other problems prevented me from using this method. To be successful, I would have had to leave the angles there until the fins dried, but then they would have themselves attached to the body with the bit of extra glue that oozed out. Also, in my first experiment I found it very difficult to position the fine correctly (perpendicular to the tube) while the angles were there. Maybe there could have been a way to make it work, but I gave up for now, and just glued the fins on normally.

Eight double-glue joints later, it actually looks like a rocket at last:
FullSizeRender 3.jpg

They are not 100% perfectly positioned; perhaps they are simply not at perfect 90 degree intervals around the tube, although I'm unclear how that could have happend. However, the error is slight, and won't be noticeable unless you really inspect closely.

I added one small set of fillets to the large fins with regular Titebond II for strength; when those are dry I'll add a layer of M&T to all 8 fins for more strength and looks.

The list of things I would do differently next time grows longer and longer, but it should *still* come out OK, assuming I don't screw up the painting.
 
Nice work - you've dealt handily with the problem spots. I think you're going to have a good looking model. I should mention that's it's very common to paint things (or at least primer them) before assembly, with various ways of assuring good glue bonds, a few of which got mentioned already. If you want the best possible fin joint strength in a non-TTW design, you can actually remove the glassine layer (with Dremel sanding drum or cut outline and peel) so that the kraft paper layer underneath will take up the glue better. It works whether you're using wood glue, CA or epoxy. The aluminum angles are great for marking the removal zones.
 
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