Quantcast

Ultimate Wildman Level Three Certification Build

The Rocketry Forum

Help Support The Rocketry Forum:

Fearoflightning

Well-Known Member
Joined
Jul 23, 2015
Messages
92
Reaction score
0
Hello!

This will be the build thread for my level three project - an ultimate wildman:)

I have yet to actually get the kit in the mail yet, but will be sure to post some pictures when it arrives. I've also got to get through finals week too....:eyeroll:

I plan on using a stratologger CF and RRC3 in my altimeter bay. I've used the stratologgers and love them, but I've never used an RRC3. I'm open to any suggestions, but from what I've heard I can't get much better. I also plan on using a TeleGPS in the nosecone. I've never used tracking on one of my own rockets before (I helped a friend with an eggfinder once) and am open to any advice. It also looks like I'm going to have to get a HAM license...

I'm leaning towards a 144" spherachute for the main, but am still considering either skyangle or rocketman chutes. Any suggestions are welcome. The only reason I would shy away from a spherachute is the number of shroud lines. I'm not fond of the look of the skyangle style. I've never used a deployment bag and wasn't really planning on using one with this flight, I would be open to it though. Thoughts?

My certification flight will be on a Loki M1650CT, but I will have a shakedown flight before that on some L that I haven't chosen yet. I've got a CTI 54 6xl laying around... I want to build this thing to handle N10000s and N5800s eventually, so I will be keeping that in mind during construction.

I haven't bought an epoxy system before and am looking at US Composites. Particularly the 3:1 medium. My school's rocketry club uses west systems, but I'm not fond of the price for what seems to be such a similar product (poor college student). I will be getting colloidal silica and chopped carbon regardless because I'm familiar with using them for club purposes. Does anyone recommend another brand or an additional epoxy for use on fin roots or centering rings? Also, what mixtures/consistencies of silica or chopped carbon seem to work best on different parts of a rocket? I've seen a few different uses.

Thanks for all the help/advice that surely will magically appear below! I'll make sure to keep this thread updated as I progress. I plan to fly it late this coming summer.

Progress will likely come in spurts, with the first over the next month. Until then, here's a picture of the paint scheme I have in mind:
L3_GP.jpg
 

cbrarick

Wildman CT
Joined
Jan 23, 2009
Messages
2,494
Reaction score
250
rocketpoxy from Tim as well.
My UW flys on a skyangle Cert 3 XL with a wildman recon drogue.

advice? My deployment charges are 6 grams each. Never fails to deploy with 6.

JMHO
 

Nick@JET

Well-Known Member
Joined
Sep 1, 2011
Messages
1,692
Reaction score
16
Subscribed! Looking forward to your build!
54-6XL - shakedown better be a high thrust motor since this is going to be heavy, but u can always cross that bridge when u get there and get the final weight.

RocketPoxy was what I would prefer West is good but imho very thin and hard to do fillets.

Comes with a gel coat NC or did u opt for a FWFG NC? Not needed right away but with a N10,000 ? I moved to a FWFG in my initial build which u can search on here Ultimate QCC ( started as an Ultimate ).

You will love the rocket it can take anything you throw at it. 98mm mount?

Mine was highly modified so came in taller and with a FWFG NC heavy at 72 lbs but had intakes and extra fin. I purchased a Rocketman 14' chute because of only 4 shroud lines which is very easy to work with. I run 7 gram charges but ejects lightly at 6gr as well, just wanted insurance.

You will have fun, mine was my most fun build to date. We will be watching!
 

PokerJones

Well-Known Member
Joined
May 29, 2015
Messages
673
Reaction score
19
Location
DFW
Interesting choice of rockets for your L3, I just did mine a few months back with the Ultimate Wildman on an AT M1315W. Very good choice.

I also used the Perfectflite StratoLogger CF's, they just work every time and I already had them.

The Sky Angle Cert3 XL is perfect for the main and I used the SA cert3 drogue as well. My final pad weight was 45 lbs.

Good luck on the build and certification, here is the build thread for more details on my L3 UW.

http://www.rocketryforum.com/showth...uot-Ultimate-Wildman&highlight=grand+optimist
 

Fearoflightning

Well-Known Member
Joined
Jul 23, 2015
Messages
92
Reaction score
0
Subscribed! Looking forward to your build!
54-6XL - shakedown better be a high thrust motor since this is going to be heavy, but u can always cross that bridge when u get there and get the final weight.

RocketPoxy was what I would prefer West is good but imho very thin and hard to do fillets.

Comes with a gel coat NC or did u opt for a FWFG NC? Not needed right away but with a N10,000 ? I moved to a FWFG in my initial build which u can search on here Ultimate QCC ( started as an Ultimate ).

You will love the rocket it can take anything you throw at it. 98mm mount?

Mine was highly modified so came in taller and with a FWFG NC heavy at 72 lbs but had intakes and extra fin. I purchased a Rocketman 14' chute because of only 4 shroud lines which is very easy to work with. I run 7 gram charges but ejects lightly at 6gr as well, just wanted insurance.

You will have fun, mine was my most fun build to date. We will be watching!
I would only fly the L990 or similar, and in low wind at that. I may end up having to buy a smaller 75mm case...

My friend has some RocketPoxy that I was going to use for roots and the like. I was going to thicken the thinner system epoxy with colloidal silica and do fillets with that. I'm interested to hear some thoughts on how that might compare to just using RocketPoxy for the whole thing. I like the idea of having a thinner epoxy for doing internal fillets as I can spread it easily.

I think I am going to opt for a FWNC. Any suggestions on where to get one?

I will also be using a custom binder design thrustplate to make the tail end look a little nicer and to fulfill my overbuilding desire:)

Thanks for all of the HAM study links! I have yet to find a place to take the test, but when I do, I'll be well prepared!
 

hobie1dog

Hi-Fi Nut
Joined
Jul 26, 2009
Messages
3,386
Reaction score
212
Location
Cornelius, NC
Last edited:

Fearoflightning

Well-Known Member
Joined
Jul 23, 2015
Messages
92
Reaction score
0
The Carolina Amateur Radio Club in Lincolnton tests 3 weeks out of every month. They don't do testing on their meeting night (2nd Thursday of the month )
http://www.arrl.org/Groups/view/carolina-amateur-radio-club/type:club

Let me know if that's were you test as I am usually one of the 3 Volunteer Examiners at the test sessions.
Ok, will do! I am currently living in Raleigh, but live a bit south of Asheville. It really depends on where I am at the time I'm confident with my knowledge where I will take the test.
 

cbrarick

Wildman CT
Joined
Jan 23, 2009
Messages
2,494
Reaction score
250
You can't get the gel nosecone anymore, so no problem.

Stay away from those 54's, just not enough thrust or average thrust. Opt for a 75 mm L - say the l2200, which fits in the 75-5120 case, and then you can turn it around in the same case with the m1297 (aka the certificationator), m1500 or m1780. One case, both flights and enough thrust to make it safe. I'd never fly mine on a l990 - just not enough push.
 

OverTheTop

Well-Known Member
TRF Supporter
Joined
Jul 10, 2007
Messages
4,360
Reaction score
1,582
Location
Melbourne Australia
It also looks like I'm going to have to get a HAM license...
I went through a local radio club that runs a couple of courses each year. Almost no money to join or do the course. If online doesn't suit your style, please consider.

VK3TRK
 

Nick@JET

Well-Known Member
Joined
Sep 1, 2011
Messages
1,692
Reaction score
16
I would only fly the L990 or similar, and in low wind at that. I may end up having to buy a smaller 75mm case...

My friend has some RocketPoxy that I was going to use for roots and the like. I was going to thicken the thinner system epoxy with colloidal silica and do fillets with that. I'm interested to hear some thoughts on how that might compare to just using RocketPoxy for the whole thing. I like the idea of having a thinner epoxy for doing internal fillets as I can spread it easily.

I think I am going to opt for a FWNC. Any suggestions on where to get one?

I will also be using a custom binder design thrustplate to make the tail end look a little nicer and to fulfill my overbuilding desire:)

Thanks for all of the HAM study links! I have yet to find a place to take the test, but when I do, I'll be well prepared!
75mm minimum defiantly - I initially thought my 98mm - M1939 was going to be 7:1 thrust ratio and after all was said and done was 5.7:1 so what you think you might fly may change. For me no way I could do a shake down without going super thunder or the like in an L. So I'm glad I didn't do a shake down since the 1939 was an ideal motor for my particular build - but again came out much heavier than your will be - 72lbs - 7000'

FWNc came from Madcow - they had n stock - but maybe can also get through Wildman

I also started with West and mixed heavy with Col. Silica and even Chopped CF and then was thick enough. Without - very runny and will wind up everywhere and RocketPoxy is already structural so you don't add anything to it. Certainly West will do you well and people have flown the rocket killa N10,000 on West - I just haven't found that West mix or wait time that didn't run too much or solidify on me too quick. Been very happy with RocketPoxy and my mix then wait time is around 40 minutes before I apply for externals.

Good luck on the build - it's a monster.
 
Last edited:

NateLowrie

Well-Known Member
Joined
Jun 28, 2016
Messages
667
Reaction score
4
I would only fly the L990 or similar, and in low wind at that. I may end up having to buy a smaller 75mm case...

My friend has some RocketPoxy that I was going to use for roots and the like. I was going to thicken the thinner system epoxy with colloidal silica and do fillets with that. I'm interested to hear some thoughts on how that might compare to just using RocketPoxy for the whole thing. I like the idea of having a thinner epoxy for doing internal fillets as I can spread it easily.

I think I am going to opt for a FWNC. Any suggestions on where to get one?

I will also be using a custom binder design thrustplate to make the tail end look a little nicer and to fulfill my overbuilding desire:)

Thanks for all of the HAM study links! I have yet to find a place to take the test, but when I do, I'll be well prepared!
Copying my point from the other thread:

I use US composites laminating epoxy (Both 3:1 and 4:1 hardener) with glass microballoons. Get a tub of microballoons from Amazon or from US Composites and it will last you for MANY builds. I mixed roughly 1:1 weight to weight. It thickens the epoxy to a peanut butter/toothpaste like consistency. You can use it with any epoxy. For external fillets, the surface is very smooth and it sands extremely well. See a picture below for how it looks on a fillet. The surface was smooth enough I went straight to 800 grit for the final sanding before finishing. It also cleans up really nice with a file for shaping the ends of the fillet.
IMG_7311.jpg




Glass balloons. I have used phenolic in the past but not carbon. I linked to the amazon page of the tub I use. It's the System Three stuff. I had a tub left over before I started using the US composites epoxy. If you are ordering the US Composites epoxy, their 3M glass microspheres on the fillers page (http://www.uscomposites.com/fillers.html) are equivalent and cheaper. That quart will last you through at least 20 builds.

Regarding other US Composites fillers:

  • I have used the fairing compound and it is decent. I found it unnecessary because the microballoons do the same function.
  • The 1/32" milled fiberglass is a good thickening agent that imparts some additional strength to the epoxy fillet. Use it on internal applications. The finish surface is too rough for external joints like fillets and it doesn't settle as well as the microballoons.
  • The 1/4" chopped fiberglass strand I would stay away from. When I mixed it into the epoxy I expected the strand fibers to separate from each other and make a nice hairball mix but in practice the strands separated poorly and just floated in the mix. Get chopped CF from another source if you want to go down the fiber route. Chopped fiber is used to impart considerable additional strength to the joint. Only use for internal joints as the peanut butter hairball is very messy and will not create anything close to the smooth fillet look you are after.


I have not tried any of the other fillers.
 
Last edited by a moderator:

Fearoflightning

Well-Known Member
Joined
Jul 23, 2015
Messages
92
Reaction score
0
Copying my point from the other thread:

I use US composites laminating epoxy (Both 3:1 and 4:1 hardener) with glass microballoons. Get a tub of microballoons from Amazon or from US Composites and it will last you for MANY builds. I mixed roughly 1:1 weight to weight. It thickens the epoxy to a peanut butter/toothpaste like consistency. You can use it with any epoxy. For external fillets, the surface is very smooth and it sands extremely well. See a picture below for how it looks on a fillet. The surface was smooth enough I went straight to 800 grit for the final sanding before finishing. It also cleans up really nice with a file for shaping the ends of the fillet.
View attachment 306827




Glass balloons. I have used phenolic in the past but not carbon. I linked to the amazon page of the tub I use. It's the System Three stuff. I had a tub left over before I started using the US composites epoxy. If you are ordering the US Composites epoxy, their 3M glass microspheres on the fillers page (http://www.uscomposites.com/fillers.html) are equivalent and cheaper. That quart will last you through at least 20 builds.

Regarding other US Composites fillers:

  • I have used the fairing compound and it is decent. I found it unnecessary because the microballoons do the same function.
  • The 1/32" milled fiberglass is a good thickening agent that imparts some additional strength to the epoxy fillet. Use it on internal applications. The finish surface is too rough for external joints like fillets and it doesn't settle as well as the microballoons.
  • The 1/4" chopped fiberglass strand I would stay away from. When I mixed it into the epoxy I expected the strand fibers to separate from each other and make a nice hairball mix but in practice the strands separated poorly and just floated in the mix. Get chopped CF from another source if you want to go down the fiber route. Chopped fiber is used to impart considerable additional strength to the joint. Only use for internal joints as the peanut butter hairball is very messy and will not create anything close to the smooth fillet look you are after.


I have not tried any of the other fillers.
Thanks for the info! I think I will be getting either the glass microballoons or colloidal silica from US Composites when I order epoxy and chopped carbon from wildman. Could someone explain the advantages/disadvantages of colloidal silica vs glass microspheres and which would best suit my needs?

As it stands now, I will use rocketpoxy for the roots of fins and centering rings when I first tack them on. I'm planning on using the US composites medium (3:1) with chopped carbon for fillets around centering rings and internal fin fillets. I will use thickened US composite for nice pretty external fillets. Let me know if y'all have any suggestions!
 
Last edited by a moderator:

Nytrunner

Pop lugs, not drugs
Joined
Oct 15, 2016
Messages
7,175
Reaction score
2,644
Location
Huntsville AL
Can I tag in and ask the benefits of chopped/milled carbon fiber or fiberglass as a filler opposed to microballoons or silica?
 

OverTheTop

Well-Known Member
TRF Supporter
Joined
Jul 10, 2007
Messages
4,360
Reaction score
1,582
Location
Melbourne Australia
Can I tag in and ask the benefits of chopped/milled carbon fiber or fiberglass as a filler opposed to microballoons or silica?
+1. For strength the chopped/milled stuff is great. I use the Q_Cell microballoons in fillets that are not particularly stressed. Very light and easy to sand.

For using the microballoons I always apply straight epoxy to the surfaces before filleting with the microballoons mix. Have yet to crack one of these fillets.
 
Last edited:

NateLowrie

Well-Known Member
Joined
Jun 28, 2016
Messages
667
Reaction score
4
Thanks for the info! I think I will be getting either the glass microballoons or colloidal silica from US Composites when I order epoxy and chopped carbon from wildman. Could someone explain the advantages/disadvantages of colloidal silica vs glass microspheres and which would best suit my needs?

As it stands now, I will use rocketpoxy for the roots of fins and centering rings when I first tack them on. I'm planning on using the US composites medium (3:1) with chopped carbon for fillets around centering rings and internal fin fillets. I will use thickened US composite for nice pretty external fillets. Let me know if y'all have any suggestions!
Your plan is a good plan, though I would make one small twist detailed below.

Regarding the differences between silica and microballoons:

Fumed silica (colloidal is the same thing, just made slightly differently) is what is called a thixotropic agent. What that means is it will thicken up the mixture when the mixture is at rest but allow it to flow when in motion. Because of this property, a small amount of fumed silica will help to prevent sagging of the epoxy but allow easier mixing. It has the largest viscosity change per amount of filler, which means you use more epoxy in the mix compared to bulk fillers and it's more costly, though that's not necessarily a problem with US composites. Note that using only fumed silica in a mix will make the epoxy mix harder to sand.

Microballoons and Microspheres come in phenolic, glass, and acrylic versions. Some are hollow and some are solid spheres. These materials are primarily filler or bulking agents and while using a bit will thicken up a mixture they don't have quite the anti-sag properties as fumed silica. The major plus is that they make the mix really easy to sand. Glass and acrylic balloons are said to decrease strength of the fillet slightly from pure epoxy alone, though you can generally expect a thicker fillet with the filler which cancels any loss out. Phenolic balloons should provide a slight increase in strength because the epoxy can penetrate the phenolic.

I learned about the strength differentiation of phenolic after I got my large supply of glass spheres. Using glass I haven't had any issue. I brought my L2 patriot down at about 25 ft/s on the main and it hit right on the fin. No damage to the fillets. I have been playing with adding mostly microballoons with a small amount of fumed silica and it's looks like the best of both worlds. You get better anti-sagging properties and it's still very light and sandable. If you can swing both a mix might your best option. I've been mixing 9:1 microballoons to silica for my tests. I may get some phenolic here shortly to play with.
 
Last edited:

Fearoflightning

Well-Known Member
Joined
Jul 23, 2015
Messages
92
Reaction score
0
Your plan is a good plan, though I would make one small twist detailed below.

Regarding the differences between silica and microballoons:

Fumed silica (colloidal is the same thing, just made slightly differently) is what is called a thixotropic agent. What that means is it will thicken up the mixture when the mixture is at rest but allow it to flow when in motion. Because of this property, a small amount of fumed silica will help to prevent sagging of the epoxy but allow easier mixing. It has the largest viscosity change per amount of filler, which means you use more epoxy in the mix compared to bulk fillers and it's more costly, though that's not necessarily a problem with US composites. Note that using only fumed silica in a mix will make the epoxy mix harder to sand.

Microballoons and Microspheres come in phenolic, glass, and acrylic versions. Some are hollow and some are solid spheres. These materials are primarily filler or bulking agents and while using a bit will thicken up a mixture they don't have quite the anti-sag properties as fumed silica. The major plus is that they make the mix really easy to sand. Glass and acrylic balloons are said to decrease strength of the fillet slightly from pure epoxy alone, though you can generally expect a thicker fillet with the filler which cancels any loss out. Phenolic balloons should provide a slight increase in strength because the epoxy can penetrate the phenolic.

I learned about the strength differentiation of phenolic after I got my large supply of glass spheres. Using glass I haven't had any issue. I brought my L2 patriot down at about 25 ft/s on the main and it hit right on the fin. No damage to the fillets. I have been playing with adding mostly microballoons with a small amount of fumed silica and it's looks like the best of both worlds. You get better anti-sagging properties and it's still very light and sandable. If you can swing both a mix might your best option. I've been mixing 9:1 microballoons to silica for my tests. I may get some phenolic here shortly to play with.
So the silica would be difficult to sand but the microballoons would be slightly weaker and have poorer anti-sag characteristics.

The phenolic microballoons sound like a good option and I like the idea of mixing a small amount of silica in. I may try that...

Thanks for the explanations!
 

NateLowrie

Well-Known Member
Joined
Jun 28, 2016
Messages
667
Reaction score
4
So the silica would be difficult to sand but the microballoons would be slightly weaker and have poorer anti-sag characteristics.

The phenolic microballoons sound like a good option and I like the idea of mixing a small amount of silica in. I may try that...

Thanks for the explanations!
That's correct. In practice, the microballoons hold the fillet radius middle of the fillet really well but slowly run at the end. What I would do is form a well with tape at the end of the fillet and then file then end down into a taper. You can see that in the shot I posted a few posts above on this thread. The fumed silica addition should give enough of an anti-sag property that the ends will not run. If you get to that point, you can contour the fillet ends the the right taper and should eliminate most of the sanding.
 

Steve Shannon

Well-Known Member
TRF Supporter
Joined
Jul 23, 2011
Messages
6,467
Reaction score
3,133
Location
Butte, Montana
It's possible to add enough microballoons to keep from running. I measure out the epoxy and hardener, then add microballoons to both parts until they are the right stiffness, then I mix them together. Because I use Aeropoxy which has a reddish hardener, I can see when the two are completely mixed.
However, epoxy with microballoons is not slightly weaker than epoxy withou; it's a lot weaker, especially in tension. That's only a problem for structural places, like fillets.


Sent from my iPad using Tapatalk
 

Fearoflightning

Well-Known Member
Joined
Jul 23, 2015
Messages
92
Reaction score
0
It's possible to add enough microballoons to keep from running. I measure out the epoxy and hardener, then add microballoons to both parts until they are the right stiffness, then I mix them together. Because I use Aeropoxy which has a reddish hardener, I can see when the two are completely mixed.
However, epoxy with microballoons is not slightly weaker than epoxy withou; it's a lot weaker, especially in tension. That's only a problem for structural places, like fillets.
I just bought the US Composites medium system (3:1), a thing of colloidal silica, and phenolic microballoons from US Composites and chopped carbon from wildman.

To address the problem mentioned above, I will likely do a smaller fillet of structural epoxy (like rocketpoxy or a mix with few to no microballoons) before I do the outer, sandable layer of the external fillets. The internal fillets don't need to be sanded to look nice so I probably won't use any microballoons in them, just silica and carbon. From what I've heard about the phenolic microballoons, they help keep the epoxy strong by saturating and forming a sort of composite. Also I plan on doing my thickening with small amounts of silica coupled with microballoons, so that should keep everything very strong.

I'm looking forward to working on this thing! Hopefully I'll get the kit in the mail toward the end of this week or next. I'm sure wildman is still swamped with orders from black Saturday, but until then, I've got one more exam to pass...

Thanks again for the info!
 

BDB

Absent Minded Professor
Joined
Aug 22, 2015
Messages
2,140
Reaction score
391
+1. For strength the chopped/milled stuff is great. I use the Q_Cell microballoons in fillets that are not particularly stressed. Very light and easy to sand.

For using the microballoons I always apply straight epoxy to the surfaces before filleting with the microballoons mix. Have yet to crack one of these fillets.
Do you mean that you basically do a two-layered fillet: First with structural epoxy and then a topcoat with epoxy+microballoons? I really like this idea. Do you need to prep the surface of the epoxy fillet to ensure that the topcoat adheres to it?
 

OverTheTop

Well-Known Member
TRF Supporter
Joined
Jul 10, 2007
Messages
4,360
Reaction score
1,582
Location
Melbourne Australia
Do you mean that you basically do a two-layered fillet: First with structural epoxy and then a topcoat with epoxy+microballoons?
Epoxy is mixed completely first, then some decanted into another container. Microballons are added and mixed into the bulk of the epoxy (remember to mix a little in at a time to keep the lumps out!). The fillet area is then brushed with the straight epoxy, wherever the fillet will be. Then the microballoon mix is applied over the top of that and smoothed as usual.

It think the layer of straight epoxy provides some transition from the stiff f/g or CF to the more compliant microballoon mix, to spread the stress and strain over a slightly thicker layer. I have yet to have a fillet crack using this approach. The process (thickness of epoxy, and other variables) is not very controlled, but seems to work for me so far.
 

Fearoflightning

Well-Known Member
Joined
Jul 23, 2015
Messages
92
Reaction score
0
Epoxy is mixed completely first, then some decanted into another container. Microballons are added and mixed into the bulk of the epoxy (remember to mix a little in at a time to keep the lumps out!). The fillet area is then brushed with the straight epoxy, wherever the fillet will be. Then the microballoon mix is applied over the top of that and smoothed as usual.

It think the layer of straight epoxy provides some transition from the stiff f/g or CF to the more compliant microballoon mix, to spread the stress and strain over a slightly thicker layer. I have yet to have a fillet crack using this approach. The process (thickness of epoxy, and other variables) is not very controlled, but seems to work for me so far.
In the past I've used a dowel a few sizes smaller than the one I would use to shape the fillets to do the structural layer. In these cases I would use 5-min epoxy for the base layer and let that harden, then go back with epoxy clay and shape that with a larger dowel. Sand and paint - always flawless.

ImageUploadedByRocketry Forum1481576278.222988.jpg
ImageUploadedByRocketry Forum1481576326.964654.jpg
ImageUploadedByRocketry Forum1481576376.723696.jpg

I of course want something much stronger than that for this rocket, leading to the discussion of fillers for use with an epoxy system.
 

Steve Shannon

Well-Known Member
TRF Supporter
Joined
Jul 23, 2011
Messages
6,467
Reaction score
3,133
Location
Butte, Montana
Do you mean that you basically do a two-layered fillet: First with structural epoxy and then a topcoat with epoxy+microballoons? I really like this idea. Do you need to prep the surface of the epoxy fillet to ensure that the topcoat adheres to it?
According to the West System handbook, if you add the second layer of epoxy within 24 hours of it curing, the second layer will crosslink (chemically join) with the first. That time is for West Systems epoxy, but as long as you do the second layer while the first layer is not fully cured you should be okay.
I've never had a problem finishing silica modified epoxy. Glass fiber or carbon fibers make it difficult to get a nice finish though. I have used a layer of silica modified Aeropoxy over a carbon fiber modified Aeropoxy layer in order to achieve a nice fillet.


Sent from my iPad using Tapatalk
 

Fearoflightning

Well-Known Member
Joined
Jul 23, 2015
Messages
92
Reaction score
0
According to the West System handbook, if you add the second layer of epoxy within 24 hours of it curing, the second layer will crosslink (chemically join) with the first. That time is for West Systems epoxy, but as long as you do the second layer while the first layer is not fully cured you should be okay.
I've never had a problem finishing silica modified epoxy. Glass fiber or carbon fibers make it difficult to get a nice finish though. I have used a layer of silica modified Aeropoxy over a carbon fiber modified Aeropoxy layer in order to achieve a nice fillet.


Sent from my iPad using Tapatalk
Good info on the bonding.

This will be my first experience using fillers to achieve certain characteristics outside of the rocketry club here, so I'm interested to get some experience with this stuff.
 

Steve Shannon

Well-Known Member
TRF Supporter
Joined
Jul 23, 2011
Messages
6,467
Reaction score
3,133
Location
Butte, Montana

Fearoflightning

Well-Known Member
Joined
Jul 23, 2015
Messages
92
Reaction score
0
I got epoxy in the mail Thursday and have been testing/experimenting/playing with it since:)

ImageUploadedByRocketry Forum1482163634.016240.jpg

Now I just need the rocket....
 
Top