BSI Glue bottles
The Thrifty Rocketeer blog continues....
One of the most common discussions among rocketeers is "Which glue do I use?"
The obvious answer is "Whatever the manufacture recommends in their instructions."
But sometimes that doesn't quite satisfy the curious or the adventurous rocketeer who wants to build their own, or vary the design somewhat.
Now, from personal experience, I can tell you that yellow wood glue has always been my preferred go-to glue for low power rocket builds. And, I have never had one fail because of the use of that glue. (Oh sure, a glasine coated body tube is a slippery surface and will always create problems, but that's another story.)
Today, I'd like to discuss BSI 15 minute epoxy, which is my go-to for builds from mid-power to high power. For even higher power, I'll spring for BSI 30 minute epoxy.
By the way, BSI stands for Bob Smith Industries... but I really can't tell you more than that cause I haven't researched the company. I know that they make two part epoxies in squeezable clear bottles of varying sizes, strengths and time-curing rates. Plus, for a large order, they will custom print labels for their product, so that your store is promoted right on the label. This is good for cross promotion and sending repeat customers back to pick up more.
I picked up my first pair of bottles at a family owned hardware store that had their own labels too.
So, a post on another website decided to open up a can of worms by asking if rocketeers kept the small plastic insert plug caps in place inside the bottle after using for the first time. It sparked a flurry of comments.
Let me clarify that virtually all BSI epoxies come in a clear, squeezable bottle, with a colorful internal plug that matches the printing, as well as the small colorful nozzle and the tiny tip cap that snaps on the end of the nozzle. So there are several ways of sealing your glue bottle, even if you remove two of the three above "caps". The internal plug does keep air from the liquid, but is not necessary once the unit has been opened.
Likewise, the tiny cap may keep the glue in the bottle, but you can't cut down the nozzle very far before that tiny cap will no longer stay on the tip. I even had one of these tiny caps split from too much force on my part, pushing them down on the nozzle too far.
The screw on nozzle could also seal the bottle, as long as you haven't snipped the tip of the nozzle off... exposing it to air.
My experience has been that air reaching the hardener will dry it out and produce a crumbly residue at the top. And while I have been told several times that this crumbly stuff won't hurt you or your project, I prefer to avoid it. It's easily brushed off.
One contributor suggests saving those inside plugs and before replacing them, giving the bottle a little squeeze to evacuate the air, and then insert the plugs. The vacuum holds the plug in place while you screw the nozzle back on the bottle.
But I have another few concerns.
First, If you have opened the bottle and removed the color plugs, be careful to replace them only into the right product. If you switch the plugs, you have effectively mixed the product and started the cure time to glue them into the bottle neck permanently.
Second, if you have removed the plugs and squeezed the contents out through the nozzle, there will be some liquid remainder in the nozzle that will attempt to flow back down into the bottle. Depending on how quickly you decide to plug the bottle once again, that remainder could/will flow back down into the well of the plug and puddle there. Assuming you use the tip cap, this isn't a problem, but it is a little wasteful.
A better solution is to keep the plugs out and to one side until you're completely done with this mixing and application, and after a good 15-30 minutes time for the liquid to flow back down into the bottle, THEN replace the plugs and cap your bottle.
This may be needlessly stingy, but this blog IS called the Thrifty Rocketeer. Plus, the bottle and plug stay a bit more clean and less tacky when you allow this to drain back over time.
Well, enough on the subject of BSI Epoxy for now. Just remember to keep your glue capped!
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