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jpedersm

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I got a new rocket for christmas wich requires epoxy to asm. I never used this stuff what should I expect does it dry fast if I get it all over my hands will that be bad? The motor mount is 38mm I was thinking abount going down to 29 mm mount what is the process in asm. this. If I stick whith the 38 mm mount where are there places to buy motors for these just to get an idea of the prices. And last in the instructions it says this "Locate the
ring 1/2” from the end of the motor
tube and allow the epoxy to set." Does this mean set the epoxy bead 1/2 in down from the end in the instructions it looks to be right on the edge and the other side where the standard setting ring is it says to move it down 1/8" of the tube wich is noticable. am I correct and the pic is a little messed up or am I wrong and the pic is right? if your confused on this please go to
https://blastzone.com/pml/ the phobos kit and step 1.
 

tibadoe

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I got a new rocket for christmas wich requires epoxy to asm. I never used this stuff what should I expect does it dry fast if I get it all over my hands will that be bad? .........
As far as epoxy goes you can purchase it in different drying rates: 5, 30, 45 minute etc. Depends on what drying time you need to work with. It's best to protect your hands with gloves, some people are alergic to different glues. Also use in a well ventilated area. Hope this helps. :)
 

kelltym88

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Applying the epoxy is not the issue. How many rockets have you built? PML kits are not like Estes kits. They have Phenolic airframes which need to be thoroughly scuffed up to accept the epoxy.

I would leave the 38mm MMT in, and get a 29mm adapter for it, this will allow you fly this on a large array of motors. But, since you had to ask where to get the motors to fly them, tells me that your experience level may not be to high with these types of kits.


This kit will accept 29mm single use motors, and 29-40/120 hobby line motors(which requires a casing). These are available at some hobby stores and at mid-high power launches. You can fly up to a "G" motor w/o certification, but some G's and any motors above require either Level 1 or Level 2 certification. Check out NAR or TRA for requirements.

The location of the forward centering ring is not crucial if you are within 1/2". Allow yourself enough room to be able to apply a good bead of epoxy on both sides after you put the ring on. I would suggest to read, and re-read the directions very carefully and dry fit all parts before applying any epoxy. 5 and 30 min is what I would reccomend you to use.

Feel free to keep asking questions, we are here to help.
 

rcktnut

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I agree with what kelltym88 said. Read and understand the epoxy instructions also, mixing exactly (proportions) as instructed is very important. You might also want to consider a motor retainer, in which you might have to adjust the mmt position a bit. You would want 3/8 in. rather than 1/8 in. of your motor tube beyond the aft centering ring.
 

jpedersm

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The bigest issue I never used epoxy and just wondering if there is any flaws with it before I start that I should know of. Also you say have some sort of ventalation I dont have a heated garge would my basement work? For the adapter to a 29mm I guess I didn't word it correct. I want to try to get my level one with this kit, but also would be doing some flights with g motors and smaller kinda wondering once we get the 29 mm adapter do we have to glue this in and the rocket will only be able to fly these size or does it come out and I have an option on flying larger motors. If this is the case I will buy another rocket later for my level one run.
 

GregGleason

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It is best to keep threads focused on one thing, maybe two, at a time to keep them focused.

Regarding epoxy, you can develop an allergy if you have consistent exposure (epoxy allergy info).

Limit your exposure by contact and fumes. I typically use disposable nitrile gloves and (most times) a respirator.

If you plan on being in rocketry for some time, I would recommend getting a good brand of epoxy, such as Aeropoxy or WEST SYSTEM.

There is a difference in laminating epoxy and adhesive epoxy. Laminating epoxy is used for layups of fiberglass or carbon fiber, whereas adhesive epoxy is used to join two or more parts together. Each vendor has there own cure time, usually based on the ambient temperature. Which means things will typically cure faster in Phoenix than Bangor. Whatever you choose to do, follow the manufacturers directions.

Also, invest in a good digital scale (one that has a "zero" feature is very helpful, I like Ohaus) if you go the Aeropoxy route, to accurately measure the amounts of resin and hardener.

Greg
 

Commonwealth.Net

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Read the instructions on the cure time and temp. required.
Most epoxy will not work below 70 degrees.
If your epoxy will not set make sure you read the temp required.

We have the FULL Aerotech line of motors.
Check out our web site.
 

MarkII

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I agree about wearing nitrile gloves but a respirator is overkill. He's not glassing a 10" airframe; he's assembling a 2.1" diameter mid-power kit. I use structural epoxy for similar builds. I wear gloves but I have never felt any need to don my respirator. Unless you are mixing it by the bucketful and slathering it on with paint rollers, most epoxy is very low-odor.

I'm a big fan of Aeropoxy 6209 Structural Epoxy, but for what he is building, either BSI Slow-Cure epoxy or Devcon 2 Ton epoxy ought to work fine. Don't bother with 5 minute epoxy; it isn't strong enough for such a build. Slower curing epoxies (those that are labeled "30 minute" or longer) are much stronger than the quick-cure variety.

Incidentally, I use disposable plastic spoons (a fresh, clean spoon for each component) to measure out Aeropoxy 6209. The ratio of resin to hardener for that version is 1:1. Measuring each component out by the spoonful has worked fine for me. For epoxies that require much larger ratios, such as 5:1, using a precise scale is a very good idea, perhaps even a requirement.

MarkII
 
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JimJarvis50

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Ah, the phobos. That was my L1 (and my first) rocket. I got the 29mm, but I wish I had gotten the 38mm to allow larger motors. As it turned out, I lost it on an I-69 - oh well.

I'm not sure if you got the 29mm or 38mm motor tube. If you got the 38mm, I would use that and then just build a 29mm adaptor. I would recommend a threaded slimline retainer. It would hold in your 38 mm motor or your 29 mm adaptor. When you fly 29 mm motors, you can apply a tape ring to the motor case above the adaptor motor tube. Then, the adaptor holds in the motor and the retainer holds in the adaptor.

Regarding epoxy, I only use laminating (rather than structural) epoxy for builds. I do this because it allows me to use various additives to modify the properties of the epoxy. I use additives such as high density thickeners, milled glass, kevlar or carbon fiber, and fumed silica. In the last 5 years, I have NEVER used unfilled epoxy. For you, I would recommend West Systems 105 resin, the 206 slow hardener, and the 404 high density filler. Then, use the filler to make the epoxy as thick as you need to for a particular step. You can get the West Stuff from the local boat store.

You should try to ventilate your basement if you can. And you should use nitrile gloves by all means. Not everyone develops sensitivity to epoxy with exposure, but for those that do, it's ususally the end of rocketry for them.

The only other thing you need to watch out for with epoxy is that it generates heat as it cures. If you make a larger batch of it (say, more than an ounce or so in a cup), it can suddenly heat up and harden. That's one reason why I use the slower epoxy (even if it slows down the build a little).

Jim Jarvis
TRA 10743 L3
 
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jpedersm

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The motor mount for this rocket is the 38 mm one but if I get the 29 mm do I need to glue this in or does the motor retainer hold it in so I can fly smaller motors andlarger ones when I want?

For the expoxy I was wondering if I can do it in my basement. It is unfinished just got the washer and dryer down there the dog kennel for when we leave and when we smoke and dont wanna go out side in this frigid weather. The windows are solid so cant open them. If I would use the expoxy down there and not come down for an hour or two would I be alright or not? If there is still a doubt there with some people I will just pack it up and waite for summer to do it in the garge, but since I have this sitting in front of me I really wanna asm. it.
 

rcktnut

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Like Mark II mentioned you are not mixing up a large quantity don't worry about using your basement to construct your model. The fumes, what little there are, are not flammable, your not going to blow up. This is not something that you are going to pass out from, you MIGHT notice a small bit of oder at worst.

I've been using it to construct rockets for 13 years in my basement without opening windows or any other type of ventilation, never used a respirator, or gloves when doing normal construction. No problems ever!!

Using large quantities for laminating at one time would be differant. You would want some ventilation then.
 

dragon_rider10

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My only experience with 2-part epoxy was when I was trying to kitbash a plastic model F-104 into a rocket. This was not successful, although it looked cool until it flew. The biggest lesson I learned from that was that you have to make sure the epoxy is properly mixed. The ratio needs to be right. If you have the amounts off, it may not cure and you'll have stuff oozing out of the joints on your rocket weeks after you think its dry.
 

ONAWHIM

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jpedersm,

I would suggest that you parse through the advice and choose your epoxy.
It will come in two parts that need to be mixed using the right proportions.

I happen to work in my basement at a workbench.
For ventilation I use a small fan to keep air moving. Not blowing directly on the project, just a breeze to move the air.

Find application tools that are disposable and a dish for mixing in.
I use one half of the plastic shell that some electrical tapes comes in as a dish.
I lay out the portions (1:1) and mix.

Practice bonding two pieces of something. You will get a feel for how it spreads and how fast it sets up.
Better to learn this way.

When its time for the real-deal, practice how you would apply without the epoxy. How you will hold your project, will the applicator tool work, etc.

Take your time when you do the real thing. You can alway mix more epoxy.
Kinda hard to undo a goof-up.

Best of luck, enjoy and have fun.

(Oh yeah, those plastic case halves my electrical tape came in, once the epoxy cures I just flex my mixing dish and the hardened epoxy comes away.)
 

MarkII

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I use cheap paper plates that I bought at the dollar store to mix up my epoxy on. I just put down equal-sized puddles of resin and hardener (for the 1:1 mix type) and then blend them together with a craft stick. I stir them together vigorously for at least 30 seconds and I make sure that all of one component is mixed together will all of the other. It's not hard to spread out equal amounts of the two parts, but if you aren't confident that you have measured them equally, just remember that it is OK to have a little bit more hardener than to have more resin. The mix will just cure a little bit faster, that's all. Don't go too much over 50% with the hardener, though, because with less resin in the mix, the final result won't be as strong. Avoid having too much more resin than hardener, though, because the resulting mix will never fully cure. If you really aren't sure that you got the proportions right but you have already mixed them together, it is better to just discard the batch and start over.

This all sounds like it is more complicated than it really is. Mixing and using general purpose 1:1 mix epoxy is actually really easy, and you will like the result when it has cured. (It will look like glass.) Also definitely use enough, but not too much epoxy in your build. More isn't always better, and once you have the parts bonded and have added appropriately-sized fillets where necessary, piling on more to the joint just adds excess weight without adding any more strength.

One other tip: keep your mix plate nearby while you are waiting for the epoxy to cure. You can touch or tap the leftover mix periodically with an applicator or toothpick to test it for hardness. If the leftover mix is rock-hard and not tacky, then the epoxy that you have applied to your model will also be cured.

MarkII
 
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MarkII

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Also, you can clean up uncured epoxy spills or drips from your clothing or work surfaces with some alcohol or acetone and a rag. But don't use either solvent to clean uncured epoxy off your skin; scrub it off with soap and water. If you get any epoxy drips onto the wrong places on your rocket, quickly wipe them off with a paper towel. You can also use a paper towel that is slightly dampened with alcohol or acetone, but go easy; getting unfinished tubes very damp with either solvent could potentially soften the tube material and even cause it to delaminate in places.

MarkII
 

WDG

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Regarding epoxy, I typically use latex or nitrile gloves. One trick I use when doing a lot of work at one time or with larger items is to wear multiple layers of gloves. If i need a clean hand I simply peel a glove (inside out to keep the mess contained.

Another idea for epoxy mixing vessel are empty (and clean and dry) yogurt cups.

OK, as far as the basement - temperature is critical for good epoxy curing. Am I the only single guy who does much of his rocket work in the living room?


Here is the most important thing I will say. Have a more experienced person looking over your shoulder on your first build. (Keeps epoxy off the keyboard.)

I love Aeropoxy. I use laminating epoxy for laminating only. I use Hexion 828 (because I get it cheap from work where I buy it in 55 gal drums. The longer the cure time, the stronger the bond typically. Follow directions on the epoxy - no experimenting unless you have tested it first. The first time you mix epoxy for structural work you will likely do one of 2 things - either mix about 4 times the amount you need or about half the amount. On long set epoxy (the Hexion is a 24 hour set epoxy) the stuff moves long after you expect it to - beautiful fillets end up as puddles on the newspaper under the rocket.

Before investing lots of money in motor hardware get involved in your local club and when the time is right borrow hardware. (Some people will not like me saying this (as some folks will always taking mooching to the extreme), but I have seen a lot of people who have bought a full set of 29mm hardware just to have it sit in their range box with some of it never used.)

Oh, one more thing on epoxy: acetone, MEK, etc is tougher on your hands than epoxy. I have found that citrus hand cleaners (Fast Orange) works great to remove uncured epoxy from your hands. Besides protecting your hands and floors, you may want to wear grubby clothes when messing with epoxy. OK, so this is more than one thing. Here, as in many areas, we have our high owner launches when the farmer lets us in the field - so Oct, Nov, Dec. Between temperature changes and varying humidity levels, fitment of rockets can become a problem. Using laminataing epoxy or thinning structural epoxy with a bit of acetone and applying a very thin coat to the inside and outside of all phenolic tubes will make your rocket less susceptible to environmental changes. (And helps keep them from getting water logged when you have a water recovery - those ponds and rivers seem to attract rockets.)

OK, so maybe this is the most important thing I will say. In rocketry I have found that folks are very helpful in sharing their knowledge and opinions. (In fact some will do it till you can't stand it - lol.) But asking for help is a good thing. At some point you need to weigh the value of the opinions and suggestions of others. One person I met said that in their club when unwanted or outrageous ideas are put forth by others the appropriate response is, "That's a great idea, You should try that... let me know how it works."
 

JimJarvis50

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The motor mount for this rocket is the 38 mm one but if I get the 29 mm do I need to glue this in or does the motor retainer hold it in so I can fly smaller motors andlarger ones when I want?

For the expoxy I was wondering if I can do it in my basement. It is unfinished just got the washer and dryer down there the dog kennel for when we leave and when we smoke and dont wanna go out side in this frigid weather. The windows are solid so cant open them. If I would use the expoxy down there and not come down for an hour or two would I be alright or not? If there is still a doubt there with some people I will just pack it up and waite for summer to do it in the garge, but since I have this sitting in front of me I really wanna asm. it.
If I recall, the phobos has through-the-wall fins. That means that the fins go through the wall of the airframe and attach to the motor tube. Once you do this, you can't remove the motor tube. Therefore, if you use a 29mm motor tube, that is the largest motor you will be able to use. So, build the 38mm version and use a motor adaptor for 29mm.

I have gone in the direction of more ventilation rather than less over time. I assure you that a 20 gram batch of epoxy is capable of putting out enough fumes to make you light-headed (been there, done that). So, if I were you, i would try to figure out how to get a least some air turnover. Does your dryer have a vent? Another option might be an air purifier with an activated carbon (charcoal) filter. I would check with the epoxy supplier for an opinion on this approach.

Jim
 

MarkII

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OK, as far as the basement - temperature is critical for good epoxy curing. Am I the only single guy who does much of his rocket work in the living room?
For the first few years after I advanced to (descended into?) BARdom, I did nearly all of my building on the dining room table. Now I use a spare bedroom down the hall as my workshop. Much better for the marriage that way. ;)

Oh, one more thing on epoxy: acetone, MEK, etc is tougher on your hands than epoxy. I have found that citrus hand cleaners (Fast Orange) works great to remove uncured epoxy from your hands.
Using solvents to remove epoxy from bare skin is also not a good idea because it will cause the epoxy to be absorbed into the skin. Not a good result. :eek:

OK, so maybe this is the most important thing I will say. In rocketry I have found that folks are very helpful in sharing their knowledge and opinions. (In fact some will do it till you can't stand it - lol.)
Ummmm, ....well? :eek: :dark:

But asking for help is a good thing. At some point you need to weigh the value of the opinions and suggestions of others. One person I met said that in their club when unwanted or outrageous ideas are put forth by others the appropriate response is, "That's a great idea, You should try that... let me know how it works."
You know, I happen to hear that a lot. Probably just a coincidence, though ... :cyclops:

MarkII
 

MarkII

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I have gone in the direction of more ventilation rather than less over time. I assure you that a 20 gram batch of epoxy is capable of putting out enough fumes to make you light-headed (been there, done that).
that's odd. I haven't noticed any ill effects.



MarkII
 

Peartree

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I think you asked twice but if anyone answered, I missed it...

If you build using a 38mm tube and buy a 29mm adapter, NO you don't glue it in, yes it IS removable. The adapter allows you to use EITHER 29mm motors (smaller, cheaper) OR 38mm motors as you grow more advanced and more experienced. Flexibility is good.
 
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