Even MORE on glues Part 2

The Thrifty Rocketeer continues...

Our tail of the construction of the Cottontail Rabbit Goonie (thank you, Peter Alway) continues in one moment...   

But first, there was a question about glues that keeps sticking around.


I had suggested gluing down your patterns or templates with School Glue paste.  This is almost like a tube of chap stick ( yes, I have used THAT in a pinch) and goes on easy. I like it because it washes off, and remains flexible or soft for, oh, several hours, if not overnight.   But I do caution to remove the template while the glue is soft and removal is easy.
You'll find a two-pack of this washable school glue paste tube on a hang tag at the check out of most convenience stores, CVS, Wal-Mart, etc.  Try to get a two pack but realize once the package is open, the glue inside begins a slow drying out. After a year, the glue that was so good at one time, may have shrunk to a withered skin or rubbery gel... unable to be applied or smeared.

The second package in the middle of this photo is a package of BSI (Bob Smith Industries) 2-part epoxy.  If you're going for strength or height in your Medium to Higher Power rocket, this is highly recommended.  There are many different combinations or styles to choose from as Bob Smith Industries has a whole line that they sell to a retailer with a display rack.

Here are the distinctions as I understand them:

  1. 5 minute epoxy is for small, quick jobs. It comes with a bottle caped in red that is a fast (5:00) hardener, and a bottle of resin in a black capped bottle.  (I believe, but I am not sure, that all black capped bottles are the same no matter what the speed of hardner. Somebody check me on that, please.) This stuff sets up SO fast you may not get it applied before it turns.  Second, it begins to turn as soon as you mix the two parts.
  2. 15 minute epoxy is much more forgiving. Most rocketeers use this when building most smaller rockets that require strength and will take a little while to mix, apply and set up. The packaging for the hardener is orange.  The second tube is also printed in black.
  3. 30 minute Slow-Cure Epoxy is the strongest, but takes the longest to set-up. This is what most rocketeers turn to for strength in their important high-power rockets. The packaging for the hardener is yellow.  But all packages have a tube with black printing.


So what do you use to mix your epoxy in?   Just as people prefer different brands or speed of epoxy, they also have preferred methods of mixing, applying or wasting their excess epoxy.



Here's one of my favorite mixing bowls...the humble condiment paper dish from Captain D's restaurants.  It's pluses are:  It's free, it has a low wall or lip, it has paper folds which easily can be flattened, allowing for complete mixing, and even better, complete removal of all the product if you spread it flat and scrape it out with a Popsicle stick. (**More on the humble Popsicle stick later.)

Now, the last part of the original photo shows a close-up of a ruler laying on the package of the Baby Bertha.  But it's not just laying casually...it's been carefully positioned so that you can read the measurement of the body tube. The top of the ruler (off camera) is at the top of the body tube, and you can clearly read that the bottom of the body tube is at 7 1/2 inches.

This is significant because I was told by a knowledgeable rocketeer that as long as the body tube was more than 7 inches, the rabbit rocket would be stable.  Please don't ask me how he knew, or the physics behind this.  That's for a class in advanced rocketry, that someone like the Rocket N00b may hold on his blog.   I'll just accept this as given.

OK, glad that you've stuck around for this discussion of glues.  I'll be returning to the Bunny Rocket fin build next time...

In the meantime, keep your glue capped and save your scrap balsa... you never know when you'll need it!

Comments

Popular posts from this blog

The End of the Line

sleeping with the enemy

Death of a Hobby