U.S.S. Atlantis - Step 8.5 (part 2), Preping the balsa parts for a smooth paint finish

The first thing I want to say here is that this is not a method that I have tested and proven and so I'm not exactly sure what the results will be. I have used sanding sealer by itself before, way back in the day, but I'm hoping for better results than I was able to get in 1977 the first time I built this kit. What I'm hoping for is to find a relatively quick and easy way to achieve a smooth finish so that when we apply the final color coat, it goes on smooth and doesn't show alot of balsa grain or tube lines.

Above you see the results of the first step which is 2 liberal coats of of the Balsa Fillercoat Primer. It leaves a very smooth "velvety" finish on the wood, sealing the finer grain but not doing much to fill the larger grain lines.

Next we apply 2-4 coats of good ol' sanding sealer, sanding between each coat until when held up to the light, you can no longer see any significant grain.

OK, the messy, tedious part is over. Now we want to prep the balsa main body tube for the primer coat. As you can see in the above pictures we want to mask the edges of the balsa pieces that will be a glueing surface. If we don't do this, the primer coat will prevent a strong glue joint between the balsa piece and the paper body tube.

Then we mask off the main body tube in a similar way using the lines we marked in step 6. Only mask off the length of each particular joint. This may seem like strong joints are one of the keys to clean liftoffs and damage free landings.

Finally, mask off the rear of the engine mount to keep it from getting primer and paint inside the mount which would cause the motors fit to be too tight.

U.S.S. Atlantis - Step 8.5 (part 1), Finishing Materials

OK, now comes the part of model rocket construction I least enjoy... Filling the grain on the balsa. This is not really covered in the official Estes instructions so I've inserted it here as step 8.5 which will cover, in 3 parts, the preping steps involved to get a smooth finish on the balsa pieces as well as the paper body tube.

Back in the good ol' days there used to exist a product called "Hobby Poxy Stuff" (thanks for the picture Jeff!) which was a thick brown goop that could fill even the most pourous of balsa grains in one thick coat.

I'm sure it was loaded with harsh chemicals and various carcinagens and stuff that makes the greenie weenie crowd cringe in fear...which I'm sure is why it was discontinued, but it worked great. It made filling balsa a breeze, and I really miss it!

So now, in the spirit of the 70's from whence this kit came, we are going back to tried and true "sanding sealer"... yes that smelly glue like substance that would fill the grain in a balsa fin in a mere 6 -8 coats. In an attempt to get that number down a bit, I'm going to try something new (at least new to me) called "Balsa Fillercoat Primer" (shown on the left in the picture below) as a first step.

Then we will follow that up with the sanding sealer for as many coats as it will take to obtain a smooth, grain free finish.

The last part of our process will be the liberal application of a thick sandable primer. I get mine at Ace Hardware but any thick flat grey primer will do the trick. This is the only treatment the body tubes will get to fill the spiral seems so we will most likely apply more coats to the body and engine tubes than we do to the balsa pieces.

U.S.S. Atlantis - Step 8, Assembling the Main Deck

Next up is assembling the balsa pieces that make up the main deck.

To protect my work mat and also to ensure we don't accidently glue anything to the workbench, I'm going to use wax paper as it states in the instructions. Some people use celophane wrap but wax paper is much easier to work with as it doesn't try to stick to itself.

So we lay out all of our pieces as shown above and make a small pencil mark 5 1/2 inches from the joint line between the forward and rear main deck pieces for the little piece that sticks out.

Once again, I prefer to use 2 part epoxy for this step though I know many modelers prefer to use cyanacrylate glue for balsa to balsa joints. I have nothing against CA glue, I just prefer the compromise between strength, fast (though not instant) set time, and strength that the epoxy affords.

When everything is glued, I fold the wax paper over the top of the assembled main deck and sandwhich the freshly glued parts in-between.

Then place a book or some other heavy object on top the wax paper to ensure that the entire assembly stays perfectly flat while the epoxy cures.

And now we have an assembled main deck, perfectly flat and as strong as if it were cut from a single piece of balsa. Our next step is one that is not in the instructions (so I will call it step 8.5). It involves sealing and priming all of the wood pieces that came with the kit so that when painted, they won't look like balsa wood. It is the most time consuming part of most simple rockets and my least favorite, but it's got to be done.

U.S.S. Atlantis - Step 7, Punching out the balsa pieces

This is another quick step, nothing other than freeing up the diecut balsa parts...



I skipped the sanding in this step due to the fact that step 8.5 will be all about finishing. I simply gathered all the balsa parts and arranged them to make sure I wasn't missing any. After all its a very old kit thats been through alot of "moves".

Yep, looks like they're all there! Next up, assembling the main deck!

U.S.S. Atlantis - Step 6, Marking the body tube

Step 6 is a fairly simple one... All we are doing in this step is marking the main body tube with the locations of the engine pylons, main deck, stabalizer fin, and detail parts.




I do this a bit differently than the instructions describe (I know, big suprise there)... First I make a photocopy of the marking guide to transfer it onto thinner paper. You'll find it much easier to align it and get it taped on tightly than the thicker cardstock one that comes in the kit.





The other thing is that I prefer to use a doorjam rather than a ruler to make the lines on the tube. I suppose either works, but I learned this trick when I was a kid and it's always seemed easier to me than trying to get a ruler to lay flat on a round tube with one hand and mark the lines with the other.




Ok, not much else to say here other than make sure your lines are straight and parallel along the length of the body tube. Next up, balsa prep.... Ooooooh fun!

U.S.S. Atlantis - Step 5, Engine Mount Installation

First off, I'm sorry for the delay in getting this posted. My son's birthday and a frantic holiday schedule are to blame.

O.K. so step 5 of our U.S.S. Atlantis build has us securing the engine mount into the main body tube:

We will be making two slight improvements to the kit design here; one structural and one cosmetic. The first modification (the structural one) will be the insertion of an additional block above the engine mount assembly that will help distribute any liftoff forces back through the main body tube:

When gluing engine mounts in place, I use a stick with a mark on it to allow me to apply glue at the correct distance in from the rear of the tube.

The second improvement will be to use the unused paper cardstock adapter ring from the engine mount assembly to dress up the back end of the main body tube:



That's it for this step... stay tuned for step 6.

U.S.S. Atlantis – Steps 1 and 2, Engine Mount Assy

Steps 1 and 2 will focus on the engine mount assembly:

We will divert from the kit design just slightly here. The Estes design makes use of one adapter ring (part# AR-2050) at the nose end and a much thinner card stock adapter ring at the rear.
This may have been to save weight or more likely cost (punched card stock is much cheaper than the heavy paper tube the AR-2050 adapter rings are cut from).

If I decide to fly this model, stronger is better so we will make use of two AR-2050s to center the engine mount in the body tube, but we will save the cardstock version for a cosmetic cover in the next step. Notice that the cardstock rear adapter ring has a notch cut out of it for the engine hook. This is to allow the engine hook to move slightly to insert a motor. We will have to cut a similar notch in the AR-2050.

ADDITIONAL NOTE: Notice that Estes part numbers (e.g. AR-2050) tell you quite a bit about the part. The “AR” tells you what kind of part it is (Adapter Ring in this case) and the 2050 tells you that it is sized to adapt between a BT-20 body tube and a BT-50 body tube.

The second modification (improvement) we will make is the addition of an engine block above the retention hook inside the motor tube. This is just an added precaution and gives the head end of the motor a little more surface area to “push” against during the boost phase. This is another inexpensive piece of insurance and I will add these to any kit that relies solely on the hook to retain the motor in position during flight.

After glueing the thrust block and second adapter ring in place, we now we have our completed engine mount:

This completes steps 1 and 2 in the kit instructions and our engine mount is now ready to be installed in the main body tube. This is actually step 5 in the instructions as steps 3 and 4 deal with ataching the shock cord and shock cord mount in the main body tube. However, as described in an earlier post we will not be using the kit supplied shock cord. So we will come back to steps 3 and 4 in a later post. It is often easier to delay shock cord atachment until later in construction with smaller models where the shock cord is to be mounted to the inside of the main body tube.

ADDITIONAL NOTE: When I first built this kit back in 1977, I used good old Elmer’s glue for most of the construction. While that’s fine for smaller rockets that won’t have to endure massive boost forces, I think that there are better options out there. Some people like to use cyanacrylates (super glues) for just about everything but I find them unforgiving and prone to getting finger prints on the exterior parts of the model (maybe I’m just sloppy). So for construction of this kit, I have chosen to use two-part epoxy as my primary adhesive. It is slightly more cumbersome to use than other adhesives due to having to mix each batch as you go, but the fact that it cures in 5 minutes, is strong and ages well (not a lot of shrinkage or brittleness) makes it worth the extra effort in my opinion.

U.S.S. Atlantis - Parts Inventory and Inspection

Upon initial inspection all but one of the parts were present. The missing part was an adapter ring (part# AR-2050). These are fairly common and I was able to find one in my spare parts assortment. By the way that brings up a good point. ALWAYS save leftover parts. Model rocketry often involves modifying or repairing a model and having a good assortment of spare parts onhand can save alot time, expense, and trips to the hobby store.

Closer inspection of each individual part revealed a few more issues which wasn't surprising given the number of years I've been dragging this kit around. The main body tube (part# BT-50) had a pretty significant crease in it where something had been set on it. I was fortunate to also have a spare one of these in my parts assortment. The other damaged items were all in the recovery system. The parachute (part# PK-12A) had a pretty large slit cut in it (possibly from a hobby knife gone astray), there was a missing tape disc (part# TD-3F) and the rubber schock cord (part# SC-1) had hardened over the years and become brittle.

No big deal on the recovery system damage, as I was planning on upgrading to a nylon parachute kit with a Kevlar shock cord in any case, so these parts are not needed and can be discarded.

I was pleased that while there was some significant yellowing of the instructions and pattern sheet (part# SP-83) as can be seen in the above photo, the decal sheet (part# KD-83) was still pretty clean. Storing your kits out of direct sunlight will help to reduce yellowing. Unfortunately, this kit had sat on a shelf in my hobby room for the last couple of years and was exposed to direct sunlight through an open window. I must have lucked out that the decal sheet was tucked in behind something and didn't get as much exposure.

Well thats about it for the parts inventory and inspection. In our next post we will begin construction!

Estes Classic Kit Build - U.S.S. Atlantis

Well I'm gonna finally dust off the old workbench this weekend and since it's been quite awhile since I started this blog I have apologize to my single follower out there (sorry Jeff) that I've been so lax in getting anything built. Actually that's not exactly true as I've done several model railroading projects recently but that's not the subject of this blog... This is a spacemodeling blog so let's build some rockets!

For my inagural spacemodeling project, I've decided to go ahead and build one of my absolute favorite old Estes kits from the 1970's... The "USS Atlantis" (kit# 1283). This kit was introduced in 1976 as something that might have existed in the "Star Trek" universe. I bought several of these kits back in the 1980s from Earl's Hobby Shop in Bellflower, CA (a favorite So Cal rocketry hang out back in the day) with the thought that I would build at least one while saving the others as collectors kits. This is the only one I managed to hang onto and since it got opened somewhere along the way, whats the harm in building it. This should be fun and will hopefully bring back some fond old memories of the last time I built one of these back in the mid-1970s.

The first thing we'll do is inventory our parts and check on their condition. After all the kit is over 30 years old...