I will NEVER Fillet another rocket again...

[K'Tesh]

I will never use white glue, or CA glue to create fillets again.... I've tried white glue, but get those D**NED annoying tiny bubbles (I don't like the song either). With CA glue, I get all kinds of weirdness if I use kicker. If I don't use kicker then I find problems with finger prints. I'm done... NEVER again will I allow those products to ruin my rockets.

However, I'll certainly use 30 minute epoxy. WOW!!! Those are some sexy looking fillets! The glasslike fillets are the best I've ever made with the least amount of work involved in making them.

I got some Bob Smith Epoxy from the LHS, and did an experiment with an engine mount... Then I did an experiment with a rocket's fins. I only wish I had discovered this years ago.

Now I feel ready to tackle the Cineroc/Omega builds...

All The Best!
Jim

[mycrofte]

I discovered that a few years ago. While mine aren't all perfect, they are about as slick as you can get with epoxy.
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[Scott6060842]

I use epoxy in most cases but for small rockets like Screamers and Mosquitoes I use Titebond mold and trim glue.

[gpoehlein]

Assuming you haven't totally given up on white glue, try Aileene's Super Thick Tacky glue - the stuff is so thick that it doesn't hold bubbles very well - it goes down more like caulk than glue. I've had really good luck with it (especially on paper rockets where you want a clear fillet).

[blackshire]

Assuming you haven't totally given up on white glue, try Aileene's Super Thick Tacky glue - the stuff is so thick that it doesn't hold bubbles very well - it goes down more like caulk than glue. I've had really good luck with it (especially on paper rockets where you want a clear fillet).Heartily seconded! I tried it after I read G. Harry Stine's praise of it in the 6th edition of his "Handbook of Model Rocketry." I've never had bubbles occur in fillets again, and its *much* less "runny" consistency makes it refreshingly easy to work with.

[jetlag]

Aileen's may be good for some, but I wouldn't use it for fillets for these reasons: It is nowhere near as strong an adhesive as epoxy is, and when subjected to heat (like from being inside a hot car or after the rocket just launched), it becomes flexible. I don't want my fins to move or wiggle at all once I secure them to the BT!
For MMX rockets though, it might work fine.

I use Jeff's technique of rolling florescent posterboard and gluing them on the inside of the nacelles of certain rockets to simulate burning rocket motors. Paper to paper bonds are great with Aileen's when I use it this way.

Allen

[ghrocketman]

I have used 15 or 30 min epoxy EXCLUSIVELY for all but the smallest of rockets since becoming a BAR back in about 1998. Simple perfect single-pass fillets that are STRONG.
Yes, they weigh just a bit more than Titebond or white glue, but the actual amount is small. The strength benefit outweighs the weight penalty anyway.

[mojo1986]

After reading this thread, I confess to being a little mystified. How do you guys work with a messy substance like epoxy and get clean, uniform fin fillets? Do you still have to mix the stuff? What is your application procedure? Surely you don't smooth the fillet with your finger! Or do you? Any epoxy that I've ever used is so sticky that it inevitably gets all over everything in sight! Not to mention that there is the threat of it setting up before I could get the fillets applied.

Joe

[Scott6060842]

Er, um ... two pieces of masking tape, mix on a scrap piece of balsa, apply with toothpick, smooth with finger, wash hands :o Probably should change that procedure.

[gpoehlein]

After reading this thread, I confess to being a little mystified. How do you guys work with a messy substance like epoxy and get clean, uniform fin fillets? Do you still have to mix the stuff? What is your application procedure? Surely you don't smooth the fillet with your finger! Or do you? Any epoxy that I've ever used is so sticky that it inevitably gets all over everything in sight! Not to mention that there is the threat of it setting up before I could get the fillets applied.

Joe

I don't know about anyone else, but I put two strips of masking tape on either side of where I want the fillet to be, then carefully apply the epoxy with a Popsicle stick, toothpick or small dowel (careful not to drizzle it in the fins or body tube). Give it a few minutes to start setting up, then remove the tape - DO NOT wait to remove the tape after the epoxy has cured.

[shrox]

I drag a toothpick through the fillet, that brings the bubbles to surface so you can then eliminate them.

[luke strawwalker]

The only thing I use CA glue for in model rocketry is emergency repairs and hardening balsa parts... IMHO it's pretty worthless for most other stuff, including fillets.

White glue is prone to the same problems you mentioned, unless you use many VERY thin layers built up to give the fillets you desire, or go back and fill pinholes until you get what you want...

Epoxy works well, but honestly is overkill, and you should use nitrile gloves to handle it, to avoid developing epoxy sensitivity... and then there's the necessity of mixing it and the waste from all that, and the difficulties in applying it... plus its heavier than water-based glues... it works, and epoxy definitely has it's uses, especially in high end MPR/HPR, but for low end MPR and LPR it's really overkill and not worth the trouble IMHO and experience...

What REALLY works well, with the great results of epoxy but the easy application of white or yellow wood glue, but without the pitting problems and runniness of white or yellow wood glue. What you should be using is Titebond Moulding and Trim Glue. It's basically a thickened type of wood or white glue... it goes on easy, just lay the fillet down with the bottle tip, and then with a damp finger, spread it evenly as you want it to appear when finished, smooth them out as you like. You can do all of the fillets at once-- no propping the rocket up doing the fillets on adjoining fins and waiting for them to cure before turning the rocket to do the next adjoining fillets/fins. Just do them all at once and stand the rocket up to let it dry-- the thickened glue won't run, sag, or drip, and the application and drying time is cut to a fraction of that required for any other method, including epoxy. The thickened glue won't form bubbles or pits unless you lay it on in EXTREMELY thick layers all at once, like between tube fins or something, with air trapped underneath (I've had that happen once, but that was the only time). The stuff dries clear, and doesn't require any sanding, though you CAN sand it if you want... basically though, if you lay the fillets down exactly as you want them to appear when dry, that's what you'll get, virtually no shrinkage, no runs, no drips, no sags... just smooth and even fillets, perfect the first time, every time. It's easy to apply, and can be easily smoothed with a damp finger, and cleaned up with a damp paper towel... no gloves or mixing or special handling required...

Works like a champ...

Later! OL JR

[Jerry Irvine]

Here's what I don't get. People are religiously attached to methods to the exclusion of others, that they have not previously posted to YORF. WTF?

[Scott6060842]

I just built an Estes Long Tom and I couldn't imagine not using epoxy, especially on the booster. An Alpha I just used Titebond.

So both for me

[BEC]

I don't know what Jerry's going on about in this thread.

I'm with Luke Strawalker. In fact I'm sure I first heard about this glue (Titebond Trim and Moulding glue, now called Titebond No-Run, No-Drip glue) for fillets in one of his posts at least three years ago. I hadn't been using the moistened fingertip before but I tried it tonight as I'm working on my second Maxi Micron (the first one, which Carl signed at NSL, has been retired with 8 flights on it). Wow what a difference just adding that tiny bit of moisture did for how the fillets smoothed into both the body tube and the fins.

For those who really want to do it with epoxy, look at jeffyjeep's build threads - notably the ongoing Black Star Voyager thread. I don't like the smell of epoxy and my wife HATES it, so it's the thick Titebond for me :).

[blackshire]

Aileen's may be good for some, but I wouldn't use it for fillets for these reasons: It is nowhere near as strong an adhesive as epoxy is, and when subjected to heat (like from being inside a hot car or after the rocket just launched), it becomes flexible. I don't want my fins to move or wiggle at all once I secure them to the BT!
For MMX rockets though, it might work fine.

I use Jeff's technique of rolling florescent posterboard and gluing them on the inside of the nacelles of certain rockets to simulate burning rocket motors. Paper to paper bonds are great with Aileen's when I use it this way.

AllenI prevent the "hot wandering fin syndrome" by making the actual fin/body tube bond (after sanding the glassine off the fin attachment areas on the tube) with yellow aliphatic resin wood glue, using a double-glue joint. After these glue joints dry, I use the Aleene's "Tacky" glue for making the bubble-free fillets.

[ghrocketman]

I smooth the EPOXY fillets with a finger moistened in denatured alcohol. I wear a rubber glove when doing so.