Anybody ever use Milliput epoxy putty?

I just found something at a hobby shop called Milliput epoxy putty. I was wondering if anybody has ever used this stuff for rocketry, and what did you think of it? Sounds similar to Fixit epoxy clay (which I know some people love for fillets and others hate). I thought I might try it on a scratch build to see how it works, but I wanted to get some opinions before I buy some.

Edit: Oh, for the record, I haven't tried the Fixit stuff either. I know Apogee raves about it, but I assume that's because they sell it.

I haven't used Milliput for rockets but I have used it quite a bit for scale models. It is very easy to work with and smooths very well with a damp cloth/finger. It can be a little tough to smear a fine edge on smooth, non-porous surfaces like plastic but lightly sanding the surface helps. I can't really speak for the structural properties but I would imagine that would be stronger than wood glue and easier to use than regular epoxy.

Have not used it on any model rocket, but use the heck out of it on Plastic Models and Model Railroad applications. As the previous poster mentioned it smooths out very well with a damp cloth or finger but I would not think it would make good fillets as once dry it becomes pretty rigid as most putties do. I doubt it will have the flexibility to work on Rockets. Great stuff for all kinds of applications on static Plastic models and railroading dioramas.

lcorinth said:

I just found something at a hobby shop called Milliput epoxy putty. I was wondering if anybody has ever used this stuff for rocketry, and what did you think of it? Sounds similar to Fixit epoxy clay (which I know some people love for fillets and others hate). I thought I might try it on a scratch build to see how it works, but I wanted to get some opinions before I buy some.

Edit: Oh, for the record, I haven't tried the Fixit stuff either. I know Apogee raves about it, but I assume that's because they sell it.

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Yes, I just discovered the Apogee FIXIT putty sales page, and yes, they rave about it...their customer comment (from a ?Professional Engineer?) is "I really like using "Fix-it" epoxy clay for fillets."

The user experience/feedback then that it would not likely be good for fillets is interesting, I'd like to hear more about people's experiences with putty.

I have used fixit with good rests a few times. It is easier and quicker than mixing epoxy and micro balloons. I can't comment on its structural efficacy. That said, in the future I will probably use epoxy with micro. I am more interested in saving weight back there than building fast.

The_Lone_Beagle said:

... The user experience/feedback then that it would not likely be good for fillets is interesting, I'd like to hear more about people's experiences with putty.

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I used FIXIT clay once, and it wasn't a good experience. I couldn't form it well as it was beginning to set. On top of that, it is heavy. So it has two negative attributes that make it not a good candidate for fillets. And I'm not even broaching it's adhesive strength, which may or may not be all that great. That said, for other hobby applications it may be great.

Something better would be a good structural epoxy with microballoons added. They sand well, at the expense of a little strength for a reasonably strong "all-in-one" fillets, that is fillets that provide strength for the fin joint and provide airflow smoothing. Or a step further, you can do structural fillets with strength amendments (e.g., laminating epoxy with short fiberglass or carbon strands) at the root base that doesn't have to be perfect and have an aero fillet (e.g., epoxy with microballoons) that sits on top of the structural fillet.

:2:

Greg

GregGleason said:

Something better would be a good structural epoxy with microballoons added. They sand well, and you at the expense of some strength for "all-in-one" fillets, that is fillets that provide strength for the fin joint and provide airflow smoothing. Or a step further, you can do structural fillets with strength amendments (e.g., laminating epoxy with short fiberglass or carbon strands) at the root base that doesn't have to be perfect and have an aero fillet (e.g., epoxy with microballoons) that sits on top of the structural fillet.

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The structural adhesives are viscous enough to keep the shape, but self-leveling enough to smooth out. So, I use AeroPoxy for fillets in one application without sacrificing strength.

SuperFil is a good sandable epoxy for filling and cosmetic shapes; it's also very light-weight.

enderw88 said:

I have used fixit with good rests a few times. It is easier and quicker than mixing epoxy and micro balloons. I can't comment on its structural efficacy. That said, in the future I will probably use epoxy with micro. I am more interested in saving weight back there than building fast.

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GregGleason said:

I used FIXIT clay once, and it wasn't a good experience. I couldn't form it well as it was beginning to set. On top of that, it is heavy. So it has two negative attributes <snip>

Greg

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JohnCoker said:

The structural adhesives are viscous enough to keep the shape, but self-leveling enough to smooth out. So, I use AeroPoxy for fillets in one application without sacrificing strength.

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Thanks for that info, everybody! Yes, the weight is a big consideration...as well as positive user experiences, that's for sure.

The AeroPoxy looks like a good candidate for fillets...anyway, I've collected a couple of fiberglass kits, with the idea of working on them this Spring/Summer...while I'm waiting, I'm collecting various experiences and ideas from the forum, and this thread is one that I'll refer back to.

I don't like epoxy putties... ones I have seen simply don't stick to things that well even under a lot of pressure, and they are often too thick to mold into shape unless you are using a hydraulic press or something. Worse yet, the huge amount of pressure needed to mold them is often enough to stick them to YOU, and not to whatever surface you want to apply it to! I guess if you heat them up they may be easier to work...