Clay Epoxy: Fix-It vs. Plumbers

There has been some discussion here recently about the Fix-It clay epoxy sold by Apogee Components.

I have never used Fix-It, but I have used plumber's clay epoxy and I was not impressed. No matter how I mixed the two parts together, there were still lots of hard little chunks that did not go away. When I tried making fillets, I could not get them smooth -- they were all lumpy and bumpy. Wiping them with an alcohol-wetted gloved finger did not help much, nor did a popsicle stick.

I had no complaints about the strength of the plumbers clay. Once it cured it was hard as rock and stronger than the material it was bonded to. I just didn't like the texture.

Does anybody have experience with both kinds of clay epoxy?

hmmm..
I've never used Fix-It epoxy, but i use the ACE plumbers epoxy clay stuff all the time.
I"ve never had that problem with this stuff, i love it.
i usually put some rubbing alchohol on my fingers before i start kneading it so it doesnt stick to my fingers.
when im doing fin fillets, i again dip my fingers in rubbing alchohol and i usually get pretty smooth fillets.
maybe you should try the ACE stuff instead of what youre using.

I really like the fix-it product sold by Apogee.

My only question (after many fillets applied) is in regards to adhesion.

Sure it "sticks", but how well? I've had fillets fail at the interface between the fillet and the fin, and I've had fillets fail at the interface between the fillet and the tube (but only after some seriously bad flight events in either case.)

Here is a picture of the epoxy I used. It is Harvey's Plumber's Epoxy Putty, purchased from Home Depot. This picture also shows how lumpy the fillets are.

Notice that the epoxy comes in a stick with both components by each other. Am I correct in assuming that the Fix-It comes in separate containers until mixed?

outasight13, thanks for the tip about ACE clay epoxy. I may give that a try.

Fore Check,
Does the Fix-It mix together smoothly, or does it contain lumps?

As for adhesion, I used this tube like a mace and beat the fins against my work bench. The wood fin cracked but the epoxy showed no sign of cracking or debonding.

Originally posted by BobCox
Here is a picture of the epoxy I used. It is Harvey's Plumber's Epoxy Putty, purchased from Home Depot. This picture also shows how lumpy the fillets are.

Click to expand...

Yeah, hmm, looking at that picture, take that package of Harveys and run it right out to the trash. (blink)

Originally posted by BobCox


Fore Check,
Does the Fix-It mix together smoothly, or does it contain lumps?

Click to expand...

Really smooth stuff - no lumps unless you introduce some foreign material by accident.

The Fix-It clay smooths out nicely, but it is very "clay like". You have to form it, then smooth it out with some water and your finger.

Forecheck...Have you tried the Fix-It paste yet? It's supposed to be a bit thinner than the clay, but has the same properties when cured.

I can't comment on the bonding strength, but is seems to hold on pretty good. Maybe some testing is in order...

I've tried the Fix-It 2-part epoxy and I tend to agree with OKTurbo; very clay-like. It kind of reminds me of plastercine (remember the stuff we played with as kids), just a tad more stickier.

I tried some on fillets and I think if you work it before it gets too firm you can have success smoothing it out. My sucess was so-so, perhaps just more time needed on perfecting technique.

However, I think Fix-It has a lot of potential using it where it can provide a bonding surface without being visible. I'm thinking here of perhaps where a cardstock transition meets the edge of a BT. For example, attaching a boattail at the aft end of your BT. Even with a CR sitting at the edge of the BT, there isn't a whole lot of contact surface between BT and cardstock transition. Perhaps if you layed down a "ring" of the putty-like material at the edge of a BT. Then bringing the transition to contact the BT-putty. Gives you more contact area. And any putty that oozes out should be able to be scraped away before it sets.

Haven't tried it yet, but I've been thinking this might work.

Also thought the Fix-It would provide a great plug on the inside of a BT if you wanted to anchor your rail buttons in a little more solidly.

Just some ideas on other uses besides the fillet idea.

Thoughts???

... Bill

Before I forget, another use where I've tried it...

Anchoring a shock cord (kevlar string) to the inside of the BT.

I tried using a glob of regular epoxy in the past, but if the epoxy was too runny it flowed too much and exposed the knot in the kevlar I had tied. If the epoxy was thick enough not to flow, it was difficult to smooth out.

But the Fix-It stuff was absolutely beautiful here. A glob of the stuff was kneaded and the kevlar sunk into it. Attach it to the inside of the BT (below the NC shoulder of course) and then smooth it over with a wet finger. Very nice, very smooth, NO chance of a chute "catching" on a rough spot.

... Bill

Eugenefl once did a bit of comparison between a number of epoxy clays out there. If I had more time, I'd do the search. Maybe he can chime in with a link to the thread he started on the topic.

Originally posted by KermieD
Eugenefl once did a bit of comparison between a number of epoxy clays out there. If I had more time, I'd do the search. Maybe he can chime in with a link to the thread he started on the topic.

Click to expand...

Yep... I had tried two different types of two part clay. Here are both of the threads and reviews:

<a href="https://www.rocketryforum.com/showthread.php?s=&threadid=3803&highlight=part+epoxy+clay">Devcon</a> & <a href="https://www.rocketryforum.com/showthread.php?s=&threadid=3849&highlight=part+epoxy+clay">SIG Epoxylite</a>

It happens I had tried both of these products. I didn't like either for one reason or another (see the threads). I like a product called SuperFil. Shadowaero used to carry it but didn't have it last time I looked. I did find it at an aircraft supply store (Google search required).

I am thinking the main difference in these products are the fillers that are used to thicken the epoxy. Superfil used microballoons, so it is light and easy to sand.

Originally posted by BobCox
There has been some discussion here recently about the Fix-It clay epoxy sold by Apogee Components.

I have never used Fix-It, but I have used plumber's clay epoxy and I was not impressed. No matter how I mixed the two parts together, there were still lots of hard little chunks that did not go away. When I tried making fillets, I could not get them smooth -- they were all lumpy and bumpy. Wiping them with an alcohol-wetted gloved finger did not help much, nor did a popsicle stick.

I had no complaints about the strength of the plumbers clay. Once it cured it was hard as rock and stronger than the material it was bonded to. I just didn't like the texture.

Does anybody have experience with both kinds of clay epoxy?

Click to expand...

The Vatsass brothers use something called powerpoxy. I could not find it locally, so I went with PC Woody (unfortunately, the only Ace hardward store that carried it washed away!...I now have to order it from ace online).

Anyway, I LOVE it, it works great!
Mix it wall and use the denatured alcohol trick to smooth it out.

Here is a photo of my canadian arrow fillets (unfinished). I also use PC woody on my high powered stuff...it really helps to "mold" the fins into the airframe.



Dave

Nice looking fillets.

What is the texture of PC Woody? Is it a clay epoxy, or more like peanut butter?

Originally posted by BobCox
Nice looking fillets.

What is the texture of PC Woody? Is it a clay epoxy, or more like peanut butter?

Click to expand...

Peanut butter--thicker in cold temps. and a little thinner in hot (they actually say this on the package).

I no longer mask off my fins, I just carefully apply it..(wipe off any mistakes with a paper towel dipped in alcohol)...usually with a wooden stick, wait aournd 15-20 minutes, and smooth it out with my finger dipped in denatured alcohol. The next day I sand them with a small piece of sandpaper wrapped around a piece PVC tube.

If you want them to come out really nice (and minimize sanding and filling), repeat the above process. It will only take a small amount to fill in any gaps.

Dave

I use Fix-It on all my low-power stuff and love it.

My prep consists of a paper plate, popsicle sticks, a couple paper towels, and a small bowl of water (I used to use rubbing alcohol, but have found water works just as well).

I pull a little bit of one clay, roll it into a small ball, then pull an (eyeballed) equal amount of the other clay and roll it into a little ball. If the two balls look the same size, I'm done measuring and I knead the two balls together. A little water on the fingers keeps the clay from sticking to your hands.

When the clay is good and mixed I pinch off enough for one fillet and roll it between my palms to form a little sausage (longer than the fillet being made). I set the sausage in the area to be filleted. I take a popsicle stick, dip the end in water, then use the popsicle stick to press the clay into the fillet. It's difficult to describe how I do this but think of starting at the top of the fillet and just poke-poke-poking your way all the way down the fillet. This leaves the surface looking very "sawtoothed" at first but it really helps the epoxy clay to adhere to both the body tube and the fin in preparation for the next step.

After the clay is poked into place, I wet the end of the stick again and, starting at the top of the fillet, drag it all the way down the fillet. The excess clay will just peel up and you are left with an amazingly well formed fillet behind. Any excess left on the fin or body tube is easily scraped away with the popsicle stick.

Be sure to have a few popsicle sticks on hand if you're doing a lot of fillets because the water tends to macerate the sticks making them less useful after a couple of fillets.

Different size fillets can be made using different size popsicle sticks, although I almost always just use regular size popsicle sticks.

I've found these fillets incredibly strong, easy to make, and look way better than anything I was ever able to do with glue, etc. Be aware, though, that this clay dries really hard, so be sure the fillet looks the way you want it before it dries. Sanding them later is a pain.

Hey Gus,
You plannin' some kind a mass attack? What's up with all the identical models?

SE

Originally posted by SteelyEyed
Hey Gus,
You plannin' some kind a mass attack? What's up with all the identical models?

Click to expand...

LOL, no mass attack.

I just need multiples of the same rocket for a school launch I do every year.

Here are the finished products.

Here's another Fix-It Clay fillet pic, this time of the aft end of an Estes CC-Express.

Note that in this extreme closeup the fillets look way better than the fins. I didn't spend any time on the fins (or the fillets for that matter) because I was pretty sure I wasn't getting this rocket back.

Even so, with minimal effort, the fillets look great.

That's why I like this stuff so much.

I used the Fixit Clay for the fillets on a 3x upscale of the Bolaero-Z. I use the same technique mentioned above, popsicle stick and rubbing alcohol. Photo attached.

Here's a close-up of the fillets after a couple of coats of primer...

Are there other retailers of Fix-It epoxy? Or does Apogee make it themselves?

Originally posted by the freshman
Are there other retailers of Fix-It epoxy? Or does Apogee make it themselves?

Click to expand...

If you are trying this for the first time I suggest buying it from Apogee, since Tim's price is good and his service is always fantastic (plus you always seem to get extra fun free stuff in the box when you order from Apogee).

The 1/4 pound package Tim sells will get you through a LOT of rockets. What he says on the website is true, you always use less than you thought you were going to need.

If you need it in bigger quantities you can alway order it direct from the manufacturer.

Aves Studio makes the stuff...

Try https://www.avesstudio.com/

Hey Gus,

Loved your mods of what looks like the Estes Cluster bomb kit for your school rocket mass launch.

I've done some rockets for a school and have tried personalizing it a bit. I've mainly just created a unique FlisKits freebie Caution Rocket with a personalized pattern.

But, I notice on your "Cranbrook Principal in Space" project rocket you actually had some images.

What's your technique???? Paper wraps? What weight? How do you attach them? How do you print them? Overcoat? Etc.

Great looking stuff.

... Bill

Originally posted by BKROSNEY
I notice on your "Cranbrook Principal in Space" project rocket you actually had some images.
What's your technique???? Paper wraps? What weight? How do you attach them? How do you print them? Overcoat? Etc.

Click to expand...

Most of your questions are answered in this review on EMRR.

Bob,

Thanks for posting that link.

Bill,

The technique is also covered here.

With regard to this thread, epoxy clay has affected how I do the wraps. Now I actually mark out a space on the wraps for where the fins and launch lug will go. I place the full wrap on the body tube and then use an exacto to cut the label paper out of the "slots" before attaching the fins and launch lug. I tried cutting the slots out of the wrap before attaching it to the body tube but it makes attaching the wrap evenly somewhat difficult.

I make the slots wide enough to accomodate the fin width (or launch lug) and about 1-2 mm extra on each side. This leaves enough bare body tube that, after attaching the fins, when I apply the Fix-It fillets they are sticking to the fin, body tube, and covering the edge of the wrap. The clay doesn't seem to affect the printing on the wrap and the application process doesn't seem to mess up the small area where clay has been popsicled away. Only thing I do different is that I don't smooth out the fillet with a wet finger since the water would run the ink on the wrap.

The clay dries cement hard and leaves no chance the wrap will peel up around the fins. Works great.