RocketPoxy
I needed to order more RocketPoxy. I hadn't notice until today that my last vat expired Jan. of 2022! Apogee had some but only two pint volume and I got the last of it they had in stock. If anybody needs/wants some, I can purge the old containers I have and put some of my new order into them. When RocketPoxy ages, it gets like stirring cold caramel. Â It's also very difficult to smooth out in that condition. I hate to have to throw away what I do have because it's pricey stuff; however, I'm not likely to use all that I'm getting next week before it's past its prime.
If interested, talk to me about it at tomorrow's launch.
Should have gotten the handy half gallon size! It's a better price per quart. 😂
If you are giving some away, I'll take some. I could always try thinning it with acetone to make it less chunky.
Quote from Eric Becher on February 3, 2023, 10:33 pmShould have gotten the handy half gallon size! It's a better price per quart.
The larger quantity is certainly the cheapest way to get RocketPoxy/volume. The problem is that it, like other epoxies, have a shelf-life. Â Eventually, the polymerization which makes epoxy such a strong adhesive begins without the catalyst (hardener). When it's fresh/new, the RocketPoxy has the consistency of stirring molasses but now it's like stirring peanut butter. Â When the catalyst (hardener) is stirred in, the polymerization ensues too quickly for it be be used like it is intended; especially, for making fillets because it it too stiff to settle.
Quote from Brian C. on February 4, 2023, 12:18 amIf you are giving some away, I'll take some. I could always try thinning it with acetone to make it less chunky.
NOOOooo...!!! Acetone is not the way to thin RocketPoxy. You can use it to cleanup mixed RocketPoxy but so will 70%, 91% and 99.9% (medical grade) isopropanol without all of the expense, smell, and skin irritation of acetone. I've contacted the chemists at Glenmarc (makers of RocketPoxy) and they insist that it should never be thinned; however, if it must be, use ethanol (denatured or Everclear — potable nearly pure ethanol) and no more than 5% by volume. I once tried thinning it more than the recommended 5% and, while it was thin enough to flow, it never hardened well. The addition of ethanol to RocketPoxy exudes an odor that you'd rather not have in the home. Good ventilation or go outside if you do.  FYI, TOO much water in drug store ethanol rubbing alcohol; don't use it!
For cleanup, I use 91% or 99.9% isopropanol (too much water in lower percentage isopropanol). When I use RocketPoxy for fillets, before it has cured completely, I often take isopropanol to the surface of the RocketPoxy fillet to take away the gloss. Â Paint then adheres better. Â It's also useful to dissolve enough of the RocketPoxy to give it a final touch-up smoothing. You'd only be removing the exposed outer surface of the RocketPoxy, so it's not jeopardizing its physical bond between fin and airframe.
When RocketPoxy is new/fresh, it can be injected.  I purchased one of these to inject epoxy.  I use the largest "needle" that it comes with when using RocketPoxy.  You can't "suck up" the RocketPoxy but because the injector plunger can be removed, I fill the syringe body and then reinsert the plunger.  As soon as I'm done injecting, the injector is disassembled and cleaned with/in 91% isopropanol.
I should have my RocketPoxy shipment next week. If you haven't used it, I can/will certainly give you some in small sample bottles. I'm sure I can find something suitable for holding the sample epoxy and catalyst. The instruction are to mix equal parts by volume. Â The specific gravity of the components at 1.48 and 1.52, close enough to 1.5 to weigh the components for a 50-50 mix. Â I have a digital scale that measures to .01g, so I properly mix small amounts by mass, not by volume.
RocketPoxy makes beautiful fin fillets. It can even be dyed. Larger quantities come with a bottle of black dye. When I built my RocketMan Miss Riley, which came with white fiberglass airframe and blue fiberglass fins, I purchased blue dye.
Uploaded files:
Oh, I get it. I currently have a pair of JB Weld 5min bottles, 4oz each that are maybe 2 years old. Have used a little more than half. One is starting to get funky. Hard to pour, cloudy, and now tiny "crystals" in it. Still mixes and cures fine though. At first I thought it was because the basement is about 59 degrees lately, but now I'm thinking it's age. Even if I throw the rest away it's still cheaper than the 5 or 6 less than 1oz syringes I would have gone through. So I might be interested in your new stuff if the price is good and quantity reasonable. Never used that stuff, but your friend Tim Van Gilligan loves it.
Remind me tomorrow. I have a few good epoxy stories from sea I can tell you.
Yeah, I have never used that stuff before. I've had good luck with the Bob Smith 30 minute epoxy that comes in those small squeeze bottles. From what I have seen of RocketPoxy in some youtube videos, it almost seems too thick to use on anything smaller than 5" diameter rockets, like original JB Weld. And everyone on Youtube seems to make a mess. Even Tim Van Milligan when he's doing the 6-part video on building the Zephyr is getting RocketPoxy all over everything trying to do internal fillets.
My method is a little more conservative. I mix very small batches of the 30-minute Bob Smith stuff (generally 10 drops of resin / 10 drops of hardener), into a Wendy's plastic ketchup cup. Mix and spread with a craft stick. Comes out great, and because it has a slow cure time, it has enough time to 'settle' into a nice smooth fillet. If I need a little more, because of the 30-minute window, I can mix up an additional small batch. But generally, 20 drops total is enough to do one side and wait for it to dry.
Copied from a discussion in the NAR community forum:
with 1/8 G10 (sanded with 36 grit and washed clean)
Bob Smith - 1,800 (Odd it sheared different on G10)
US Composites - 2,600 (significantly less if you add any filler)
West Systems - 2,600 (significantly less if you add any filler)
JB Weld -- 5,200 (this surprised us!)
FRESH Rocketpoxy -- 4,800 (this product will loose "strength" as it ages on the shelf in the can)
ProLine -- 4,200 (Not sure of which version as i know the formula has changed since)
If you're building fiberglass of carbon fibre, BSI is not a good choice for strength. It's a good go-to epoxy for many things and I use it myself.  I have 5-min, 15-min and 30-min plus the 20-min finishing epoxy.  If you're using it for fillets, you should have micro-balloons.  BSI, itself, isn't a good filler epoxy as it has not solids. Stir in micro-balloons (not to be confused with Chinese spy balloons) or some finely chopped up fiberglass threads — micro-balloons are just so much easier but, like fiberglass dust, you don't want to inhale them.
JB Weld, especially the 24-hour JB, is extremely strong because it has steel in it. This is what you'll want to use to adhere your retainers to fiberglass MMTs because it also have a very high glassing temperature in contrast with other epoxies.
The nice thing about RocketPoxy for fillets is that you can apply it to the fillet localation and lightly smooth away excess.  Then, wait until it get to leather stage (around an hour after first mix) and use some fondant ball tools (dipped in isopropanol if necessary) to smooth out a nice even fillet.
Quote from Eric Becher on February 4, 2023, 9:05 amOh, I get it. I currently have a pair of JB Weld 5min bottles, 4oz each that are maybe 2 years old. Have used a little more than half. One is starting to get funky. Hard to pour, cloudy, and now tiny "crystals" in it. Still mixes and cures fine though. At first I thought it was because the basement is about 59 degrees lately, but now I'm thinking it's age. Even if I throw the rest away it's still cheaper than the 5 or 6 less than 1oz syringes I would have gone through. So I might be interested in your new stuff if the price is good and quantity reasonable. Never used that stuff, but your friend Tim Van Gilligan loves it.
The shorter cure time epoxies tend to polymerize moreso than the long cures; however, they all have a shelf life. I've put several $hundred into the fiberglass C/W HV-ARCAS. I just built its avionics bay with two MARSA33LHDs which run about $200 each. Sundry other bits and pieces like the motor retainer are also pricey. Â I want the best for this beast to securely hold it together. Buying fresh epoxy is a small drop in the bucket.
I never use the dime-store epoxy syringes. Individual epoxy and catalyst in bottles (BSI, US Composites, West Systems) or cans.
I've grown to loathe Tim's videos. Too many follow his methods as if they're the word of god; not to mention, he's sloppy in many of his videos. You don't need to buy RocketPoxy from Tim and Co. Others carry it and cheaper than Apogee — Tim Lehr (Wildman), Chris Short (crocketty), Robert and Gloria (Animal MotorWorks), etc.
Remind me tomorrow. I have a few good epoxy stories from sea I can tell you.
Drag Queen epoxy story time! 🤪
"Drag Queen epoxy story time! 🤪"
I'm not sure what this means, but if you don't want to hear it, you don't have to.