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ewomack

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Hello - I was hoping to have built an L1 kit by now, but the "world situation" sort of delayed everything.

In any case, I would like to use epoxy for the first time on the L1 kit (I was thinking of a Madcow Super DX3), but instead of "practicing" on a relatively expensive kit, I would rather get used to using and setting epoxy before putting a drop of it on the kit, probably for obvious reasons. 😁

Does anyone have any recommendations for practicing and getting comfortable with epoxy for those who have never used it previously? I've heard the longer the setting time, generally the better, but I'm obviously extremely new at this. Would it be as simple as just buying some tubes and some extenders and just epoxying them? Would this prepare me for "the real thing?"

Thanks!
 

Funkworks

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I practiced using it on my first few cheaper rockets. (Also for small household repairs over the years). I never noticed anything particular about it compared with school glue, so I guess I don’t have any real tips.

Just mix equal amounts with a thoothpick on a piece of cardboard and apply. Clean any excess ASAP and relax. That’s what I do.

You can always try with scrap wood or plastic first. Or maybe clean refuse like an empty cereal box. Enjoy! I like gluing stuff.
 

Steve Shannon

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Hello - I was hoping to have built an L1 kit by now, but the "world situation" sort of delayed everything.

In any case, I would like to use epoxy for the first time on the L1 kit (I was thinking of a Madcow Super DX3), but instead of "practicing" on a relatively expensive kit, I would rather get used to using and setting epoxy before putting a drop of it on the kit, probably for obvious reasons. 😁

Does anyone have any recommendations for practicing and getting comfortable with epoxy for those who have never used it previously? I've heard the longer the setting time, generally the better, but I'm obviously extremely new at this. Would it be as simple as just buying some tubes and some extenders and just epoxying them? Would this prepare me for "the real thing?"

Thanks!
Search for and download the manual from West Systems and watch videos from the Gougeon Brothers and you’ll get some good hints and techniques to try. Then, just build rockets.
Also, Aircraft Spruce has instructional kits and books for composite construction.
 

prfesser

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I'll second dhbarr's suggestion. Glue a few bits of balsa or stiff cardboard to a tube, to mimic fins. If you have some powdered chalk (carpenter's chalk line stuff), tempra paint powder, graphite powder, soot, etc., add enough to make the epoxy clearly visible. Makes it much easier to see misteaks.

Also: the bottom of an empty beverage can is a nice cup if you need to mix more than a couple of drops. Tear off the tab so the can will stand properly.

Best -- Terry
 

dr wogz

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I knew someone that though the time was the mixing time: 5 minute means mix for 5 minutes..

mix thoroughly. I like to cut the tip off a Popsicle stick so I have a flat edge to scraps & scoop up off the mixing surface.

Fold the epoxy into itself, don't mix & swirl & spread it out.

A rag in one hand, and apply with the other.


You can practice holding it on the end of a stick by substituting honey.. dip a Popsicle stick in honey, and try to transport the glob to your work area without spilling it!

Plan out how you are going to do the assembly; run thru your steps. Ensure you have supports & other things at your disposal; Tape, etc.. with in reach. (You will get a fin in place, and it'll require .. something to hold it upright, in place, etc.. make sure you have this accounted for.)

Leave it for 24hrs. even though it's the 5 minute kind, it'll take a few hours to completely cure.
 

dhbarr

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Oh yeah, I like to put down parchment paper squares and wear two pairs of gloves -- I'm super clumsy so I get a couple of free mistakes before I ruin another pair of jeans and possibly the tabletop.
 

BABAR

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Definite plus 1 on gloves. Don't want to develop skin allergies
 

richP

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Get one that sands easily, lol...
You could buy a cheap kit and work on assembling it, and you'll have another rocket as a result. Which epoxy were you planning on using? There are many kinds, and some have much steeper learning curves than others. Stay away from the 5 minute stuff, sets too quickly. To start, you could just try the standard 15-30 minute Devcon or JB Weld from Home depot
I've found that having the proper accessories really helps in getting the best results.
For example:
When using Rocketpoxy; having small medicine cups, popsicle sticks, gloves, a small scale, syringes and rubbing alcohol really help and only cost a few dollars.
For West Systems, much of the above accessories can be used, in addition to the pumps for each component, and a good additive (silica, etc.).
 

Zeus-cat

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As others have said, wear gloves. I used to skip the gloves, but I have been very lucky not to have developed any allergies so far.

I always give the epoxy more time to cure than it says on the package. I give 5 minute epoxy 30 minutes or so. Ambient temperature and how well it is mixed make a difference in how fast it cures.

Most of the epoxy we use will generate heat while curing, the more epoxy the hotter it gets. If using it on plastic be careful. I have put epoxy in nose cones along with weight for stability reasons and put the nose in an ice bath to keep it from distorting the plastic. It takes longer to cure that way, but better safe than sorry.
 

David Schwantz

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I have been doing this for over 50 years. Whenever I get a new glue, anyy type, I always practice with it. I will glue a popsicle stick to the type of material I am vwanting to use. This not only tests setup time but also strength.
 

Jmhepworth

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Get a Mach 1 kit. They are rather inexpensive. And just jump in and buy some Aeropoxy. I started with 30 minute stuff, and although it works fine, you might as well practice with what you will want to use when you build something bigger.
 

o1d_dude

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Popsicle sticks...they come in different sizes and can be shaped to fit whatever radius you need for your fillets. I buy mine from Hobby Lobby. They make great applicators and you can epoxy a popsicle stick to a dowel or a length os square wood to use when you need to apply epoxy way down into the tube...like putting a fillet around the top of the motor mount, etc. Also works from the aft to apply epoxy where the motor mount will go, or making fillets in a through the wall fin can.

Once the WuFlu pandemic becomes politically unpopular/inconvenient you should able to once again find nitrile gloves at Harbor Freight. Right now, get there early in the morning right after their delivery truck shows up. I prefer the largest suze I can find as it makes the gloves easier to remove.

Corn starch or baby powder is handy for eliminating the spots on the gloves that become sticky from the epoxy. Shake a bidt of powder on the gloves and roub them together. You might even want to keep a small paper bag with starch or powder in it for that purpose. Just put you sticky mitt into the bag and get some powder on the gloves and rub them together.

I mix my epoxy on cereal boxes I have cut up into 4”x4” squares (approximate) and used itunes cards or something similar to mix the epoxy. It’s a holdover from the days when epoxy would melt foam cups. I pour/squirt equal sized pools of Bob Smith epoxy on the cardboard and then mix together with a popsicle stick using the universally ill-advised stirring method. Then I take an iTunes card and mix using the scrape method. The pool method of measuring ONLY WORKS for 1:1 mixtures like Bob Smith or Aeropoxy.

I sometimes use a worn out utility knife blade to scrape not yet cured epoxy from locations where it is unwanted. Alcohol soaked squares of blue paper shop towels can also be used but with less accuracy.

I store my epoxy bottles/cans/etc in Sterilite “Airtight” containers. These are the ones with the blue foam seals around the lid. They really do prevent the smell of epoxy from escaping. This is important because epoxy seems to prefer the same temperatures for storage that we rocketeers prefer and I bring my Sterilite container(s) into a spare bedroom during the summer and winter when temperatures are extreme (high or low). My child bride hasn’t complained at all...which is important long term.

Here endeth the tale.

Undoubtedly others will add their tips and tricks and we’ll all learn something from this.

Make your mistakes on a sacrificial rocket kit. Once you get your chops up to snuff, move on to that rocket you really want to build right now.
 

John Kemker

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Get a Mach 1 kit. They are rather inexpensive. And just jump in and buy some Aeropoxy. I started with 30 minute stuff, and although it works fine, you might as well practice with what you will want to use when you build something bigger.
I agree with this 100%. However, make sure you get the structural Aeropoxy (ES6209) and not the laminating Aeropoxy. While, yes, you could put something together using the laminating epoxy, the ES6209 is a better choice and mixes 1:1 by volume or weight.
 

Chad

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I would read up on surface prep too. There's lots of good threads on how to prepare materials for bonding, it can make a huge difference on the quality of the bond.

The already mentioned gloves are a must have and the fumes aren't that great either. Make sure you're in well ventilated area. I don't think you need like a full body hazmat suit but a small fan blowing across the work and away from you is a good idea.

Also, not all epoxy systems are 1:1 ratios. I picked up a little digital food scale off Amazon so I can get pretty accurate resin/hardner measurements.

PS I've been thinking of switching from Aeropoxy to West because I can get it locally or with free-shipping from walmart.com
 

John Kemker

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I would read up on surface prep too. There's lots of good threads on how to prepare materials for bonding, it can make a huge difference on the quality of the bond.

The already mentioned gloves are a must have and the fumes aren't that great either. Make sure you're in well ventilated area. I don't think you need like a full body hazmat suit but a small fan blowing across the work and away from you is a good idea.

Also, not all epoxy systems are 1:1 ratios. I picked up a little digital food scale off Amazon so I can get pretty accurate resin/hardner measurements.

PS I've been thinking of switching from Aeropoxy to West because I can get it locally or with free-shipping from walmart.com
Yeah, Chad, I hear ya, but Aircraft Spruce isn't too far from where I live, so I just go pick my Aeropoxy up. [grin]
 

epflyer

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I mix my epoxy on cereal boxes I have cut up into 4”x4” squares (approximate)
I used to use magazines to mix on. When the leftover glue cured, I would tear the page out and toss it in the can. Now I don't have any magazines. When I recently built my 3" fiberglass rocket I needed more volume. I recycled some yogurt cups and they really work well. Just peel the label off and rinse them out.

MixingCups.jpg
 

ether

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also practice keeping it away from things you don't want to glue together and practice cleaning up with alcohol, best advice is being patient and not trying to glue too many things at the same time and thinking through how/where the epoxy will flow. 2nd the suggestion of gluing tube fins using inexpensive tubes, would be a great learning experience.
 

KilroySmith

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There's a lot of household stuff that you can repurpose, especially when getting started, but I found that just going to Amazon reduced the stress between me and my wife when I was building regularly.
1. A small scale to accurately measure the components. The truth is that you can make fine epoxy by eyeballing the measurements, but it's cheap enough to do right: https://www.amazon.com/Weigh-Gram-Digital-Jewelry-Kitchen/dp/B06Y61YW7S
Besides, it can also double for measuring ejection charges...or reloading ammo for your 9mm.
2. Something to measure the epoxy in. The medicine cups that come with kid's cough medicines are great, but if you tried to buy enough cough syrup to supply you with epoxy measuring cups, you'd probably get arrested. Instead: https://www.amazon.com/gp/product/B0190UKGL8
3. Something to mix your epoxy with. Popsicle sticks are great for larger quantities as are bamboo paddles, and the thick side of gourmet toothpicks are marvelous for tiny quantities:
4. Gloves. I use 3 mil Nitrile gloves from Harbor Freight; they're cheap especially if you buy them the three or four times a year they go on sale.. You'll rip one or two when you're learning to put them on, but the thin ones are much, much easier to work in than the thicker ones.
 

neil_w

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I use dollar-store plastic shot glasses (something like these: https://www.amazon.com/Glasses-Plas...ds=plastic+shot+glasses&qid=1597189696&sr=8-5) for mixing; works well for small quantities, maybe not for HPR fillets. Could reuse them for small quantities, just let the epoxy in them cure fully, and then it's just a slightly smaller cup. :)

Gorilla-grip gloves (https://www.homedepot.com/p/Gorilla-Grip-Gorilla-Grip-Large-Gloves-3-Pair-25077-060/300867965) rather than the disposable nitrile gloves, because they work great and are easy to put on and off. If a bit of epoxy gets on them it's no biggie, I just wipe it off with alcohol. But I really try to keep it off. Actually I use those gloves for lots of general-purpose tasks, they're cheap and comfortable and give good grip.

For my low-quantity LPR uses I stick with BSI 15-minute and 30-minute in the bottles. I used to use the 30 minute exclusively, but then switched mostly to 15-minute because (a) I don't need all the working time, and (b) BSI rates the 15-minute as most flexible, and that seems like a good thing generally. I don't use 5 minute because I'm never in that big a rush with epoxy.
 

OverTheTop

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I use dollar-store plastic shot glasses
Same here. Disposable cups make for good containers when mixing larger quantities.

Don't ever think "I will be really careful when I mix this up so I won't need to change out of my decent jeans and shirt". If you are being careful you will change into work clothes.

Generally the slower the cure the stronger the epoxy, mostly. Data sheet is king for working out which is suitable for the application. Personally I stay using West System 405/206 (slow) and just put up with the long gluing time. I rarely use anything quicker. YMMV.
 

John Kemker

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I found that price-wise, Horrible Fright costs more per glove than Aircraft Spruce. HF sells in boxes of 50, while Aircraft Spruce sells in boxes of 100.
 

rklapp

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also practice keeping it away from things you don't want to glue together and practice cleaning up with alcohol, best advice is being patient and not trying to glue too many things at the same time and thinking through how/where the epoxy will flow. 2nd the suggestion of gluing tube fins using inexpensive tubes, would be a great learning experience.
E45D7B5A-BD5B-43B0-B331-86151D238845.jpeg
 

prfesser

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Scraps of balsa left over from kit fins can be split or sliced easily for mixing sticks of various widths. Cut the end square or to a chisel point.
 

Charlee

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I prefer the more rigid feel of a wooden cloths pin for mixing and applying epoxy. To get the full working time of the epoxy, I mix the components on a flat surface, like the plastic top to a coffee can or other food product, and run equal length beads of each component next to each other before mixing them. Leftover cured epoxy just pops off the plastic top when it is flexed so that it can be used for many years.
 

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dr wogz

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Leftover cured epoxy just pops off the plastic top when it is flexed so that it can be used for many years.
yet many seem to think it does stick / bonds to plastics..
Hence why I constantly say "no" to epoxy questions for plastic parts
 

boatgeek

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If you're using a cup, mix like you would mix pancake batter--lift up from the bottom and scrape the sides/bottom until it's a consistent color and texture. At least out here, you can find nitrile gloves easily at the Cash & Carry type warehouse grocery stores that normally serve the restaurant trade. They tend to be pretty well stocked now.
 
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