Author Topic: Old Superfil (Read 2895 times)

Robertc · « **on:** February 18, 2020, 04:12:20 PM »

I have some Superfil for fillets that I've had for around 9 years and it's no longer "creamy" (for lack of a better term)
Hard to mix, even after heating a bit and hard to smooth out. Toss it or is there some way to get it softer?

Howard Rush · « **Reply #1 on:** February 18, 2020, 04:36:30 PM »

Mine came that way from Aircraft Spruce. When I asked about it, they said it was a new batch. I use it around the house as waterproof spackle.

wwwarbird · « **Reply #2 on:** February 18, 2020, 07:27:07 PM »

Quote from: Robertc on February 18, 2020, 04:12:20 PM

I have some Superfil for fillets that I've had for around 9 years and it's no longer "creamy" (for lack of a better term)
Hard to mix, even after heating a bit and hard to smooth out. Toss it or is there some way to get it softer?

I had a batch that was probably about that old by the time I finished it off last year. The last couple years it did seem like it had gotten more difficult to mix but if I just kept at it for a bit it would gradually soften and end up mixing and curing just fine. I figured that must have been a result of the chemicals going to work and eventually doing their thing. I never tried heating it, I think that might actually worsen the problem though.

Mike Haverly · « **Reply #3 on:** February 18, 2020, 09:24:40 PM »

Put it in the microwave, time varies. 10 to 15 seconds and check it. Monokote gun works too. When it's warmer "kicks" in a shorter period of time so keep the heat gun handy. I have part of a jar fifteen years old
that's still ok, just have to heat it up.

Perry Rose · « **Reply #4 on:** February 19, 2020, 05:25:29 AM »

I have some that's a couple years old. I noticed that the hardener had separated, there was a dark liquid at the bottom of the jar. I mixed it up and it's creamy again.

Avaiojet · « **Reply #5 on:** February 19, 2020, 06:54:26 AM »

Quote from: Perry Rose on February 19, 2020, 05:25:29 AM

I have some that's a couple years old. I noticed that the hardener had separated, there was a dark liquid at the bottom of the jar. I mixed it up and it's creamy again.

Perry,

I personally wouldn't trust an old product on my models, especially a product that goes on well before the finishing toppings. No confidence.

Besides, blue isn't my favorite color.

Why aren't you using micro-balloons? I have unlimited success with the product. Plenty of confidence.

CB

Mike Haverly · « **Reply #6 on:** February 19, 2020, 08:00:39 AM »

There's nothing wrong with old Super Fil. It still behaves the same and it normally gets covered with paint.
Yes, the hardenerer separates. I store the container upside down, warm it up and stir. Works fine.

Avaiojet · « **Reply #7 on:** February 19, 2020, 09:01:04 AM »

Quote from: Mike Haverly on February 19, 2020, 08:00:39 AM

There's nothing wrong with old Super Fil. It still behaves the same and it normally gets covered with paint.
Yes, the hardenerer separates. I store the container upside down, warm it up and stir. Works fine.

Sure, that's being said, but I still wouldn't take the chance, especially with the quality models I crank out.

Micro-balloons don't separate. And you have full control of the mix.

Mix it as a light glue or mix it to spread like drywall compound. Easy as pie and it sands soooooooo nicely.

I use this on canopies with a tad of paint, when done the mix needs no sanding, same with fillets. Just a light scuff. Check out the GBR-3, I mixed a tad of artists acrylic black. Perfect every time.

The best thing is it's not blue.

Randy Powell · « **Reply #8 on:** February 19, 2020, 12:14:54 PM »

I like Mike's idea. I've used acetone to thin it a bit. Makes it lay out better.

John Leidle · « **Reply #9 on:** February 19, 2020, 09:50:34 PM »

A long time ago I found dark brown crystals in the brown part of my Sig Epoxolite. When I mixed the 2 parts the crystals didn't mix in or dissolve. So I started heating up the brown part before adding the white half. This pryor heating of the brown crystals worked out. So I would guess somehow mixing any of the Superfil that is separating would work.
But if you use the microwave to heat the epoxy ... be careful the epoxy can get very runny & can burn the crap out of your fingers if you spill it on your self. If my buddy Lee was still around he would tell you .
I always used the hair dryer.
John L.

Howard Rush · « **Reply #10 on:** March 28, 2020, 12:56:45 AM »

Got some new Super Fil. After keeping it in quarantine for a few days (it came from Aircraft Spruce), I used some. Works as well as everybody says it does. So my first batch was bad from the get-go.

In answer to Robertc, toss it or use it to fill cracks in the driveway. If it's like mine, it's essentially useless, and the new stuff is just fine.

wwwarbird · « **Reply #11 on:** March 28, 2020, 10:24:30 PM »

Good to hear Howard, I thought it was really odd that you (or anyone) wouldn't care for it, great stuff IMO.

Steve Dwyer · « **Reply #12 on:** April 01, 2020, 02:50:40 PM »

Quote from: Avaiojet on February 19, 2020, 09:01:04 AM

Sure, that's being said, but I still wouldn't take the chance, especially with the quality models I crank out.

Micro-balloons don't separate. And you have full control of the mix.

Mix it as a light glue or mix it to spread like drywall compound. Easy as pie and it sands soooooooo nicely.

I use this on canopies with a tad of paint, when done the mix needs no sanding, same with fillets. Just a light scuff. Check out the GBR-3, I mixed a tad of artists acrylic black. Perfect every time.

The best thing is it's not blue.

Charles,

What are you mixing the micro balloons with to make a sandable fillet? I have used 30 min epoxy but it is not sandable.

Steve

Avaiojet · « **Reply #13 on:** April 01, 2020, 04:25:07 PM »

Quote from: Steve Dwyer on April 01, 2020, 02:50:40 PM

Charles,

What are you mixing the micro balloons with to make a sandable fillet? I have used 30 min epoxy but it is not sandable.

Steve

Steve,

What part of the model did you apply the Epoxy? Apply heat with a heat gun and you can remove it or spread it but I believe the mix was too wet if difficult to sand.

Couple of things.

First, I never apply fillers over bare wood. I think the "iron on" guys may, I'm not sure?

I treat the wood like most modelers do, 50-50 clear dope and dope thinner. I use only SIG dope and SIG Thinner adding more clear dope as you get close to filling the grain. Scratch it up before applying fillers. I board mine out a bit but I don't thin wood by over sanding.

The wetter the mix is the more challenging the sanding is. A simple given.

I only use 5 minute and 20 minute "hobby grade" Epoxy. From Hobby Shops or Hobby product suppliers.

Two cups. One with the Hardener the other for the Epoxy. I mark the cup bottoms, E or H.

Decide how much you need? Place a bit of hardener in one cup and Epoxy in the other.

Add a tad of Micro-Balloons till the mix is really dry but wet enough to stick. Mix each cup separately using a different stick for each cup mix. Obviously for filling, the dryer the better, still has to stick. To dry, add Epoxy to the E cup, to wet, add Micro-balloons.

I place a tad of yellow artists acrylic paint, a drop or two in one cup and mix. When everything is light yellow you can now mix the two together. Yea, you use a bunch of sticks, Starbucks sticks for free.

The color lets you know when the mix is over. You don't want to over mix because you'll loose application time. Important.

I don't know where your mix was placed?

You can put a piece of thin masking tape on each end of where the fill is going. No point in putting it where you don't need it. Pull the tape before it sets up. You can tell when it's setting up it gets tacky, I can wet my finger in my mouth then rub it gently on the edge to feather the edge if I get the mix at the right time.

You can put masking tape back on each side so you don't over sand to the balsa.

I use a good deal of the 5 minute mix so I can get back to work in a short period of time.

Spread it on with credit cards that have been canceled.

Keep in mind, many imperfections can be dealt with well after silk is applied and filled with 3 or so coats of clear dope or Deft Wood Sealer lacquer. Clear dope over open bays and sheeted areas or Deft Wood Sealer lacquer over sheeted areas, I've used both. Other modelers have also.

Then you have the high build primer over the cleared silk next, and as Robert says, "Most of it winds up on the floor." Last is the use of auto putty sparingly.

These wheel pant halves are for a TEXACO 13. A semi-wet, semi-dry mix. A tad of green blue paint to match the color of the fiberglass. Unnecessary but cute.

I did a wet skim with my finger on the left one, needed only a minute or so of sanding. The radius at the edge, I had a few layers of masking tape there, that radius was cut with a #11 blade in the tape before the mix was applied. The unneeded side of the tape was removed. This task was done while both halves were glued to 3/32 light balsa that had the correct outline for the scale wheel pants.

If I didn't have the balsa and the tape, I'd be there all day creating correctness for that wheel pant half. This was quick and easy. Done no sanding to the one on the right yet. More tasks still have to be done to these items.

I hope this helps.

Charles

Avaiojet · « **Reply #14 on:** April 01, 2020, 06:21:54 PM »

Steve,

I just did the bottom of another wheel pant with a semi-wet mix.

If you look closely, there's not much there and it's spread just about the way it needs to be sanded.

That white line on the wax "fence" paper is from using a stick to remove excess mix not needed.

Here's a link that will take you to a Build over at CFC Graphic's vendor's corner. It's the GBR-3 build.

Plenty of uses using Micro-Balloons and a few tricks. Please take a look.

Charles

https://stunthanger.com/smf/cfc-graphics/gee-bee-r-3-build!-semi-scale-cl-stunter!/

Steve Dwyer · « **Reply #15 on:** April 02, 2020, 07:25:15 AM »

Charles,

Exactly what is the brand epoxy you are using that allows sanding?

I only use epoxy and micro balloons for the fillets where the wing and control surfaces meet the fuse.
I have used the masking technique you describe and I often use Naptha to smooth the edges to eliminate a step in the event the remaining thickness was too much. Acetone is too aggressive and tends to remove the prime coat of Butyrate sealer.
I typically use the 30 min Bob Smith brand adding the balloons the get the proper stiffness so the mix retains the shape fillet I want. Normally I do the top and bottom areas separately to reduce the chance of movement before curing takes hold.
I always apply a clear Butyrate mix to seal all the balsa before doing anything including silking the wing or epoxying the fillets.
The results are beautiful and even though I've learned to minimize the size (width and thickness) of the fillets I realize I'm adding undesirable weight.
I am leaning toward using Polyfiber Suerfill that many have recommended. It is light and sandable.

My results using the Bob Smith Epoxy adds weight and does not sand. The epoxy hardens to a smooth non-sandable finish. I have also tried the 5 min BS Epoxy with the same non-sandable results.

What product are you using that allows easy sanding?

Steve

Dan McEntee · « **Reply #16 on:** April 02, 2020, 08:07:56 AM »

Steve;
When making fillets, I use the Bob Smith Finish Cure Epoxy and micro balloons. It's a different mix of epoxy. I add enough micro balloons to the mix to get it to like cake icing or a bit thicker, then apply with my favorite tools and methods. When you add anything to an epoxy mix, it slows down the curing time greatly. The 20 minute handling time can become 2 to 3 hours or more. You don't need to mix a lot of epoxy, because you add so much micro balloons that you usually have plenty for a wing or tail surfaces. I think I mix about 1/4 ounce of each, then the rest in micro balloons and it fill up one of those little graduated mixing cups.When I have the fillet looking like I want it, I wait a while for it to start kicking, and I did my finger in alcohol and drag out the edges. I almost never need to sand them, but if I do, they sand fairly easy because that is what the finish cure epoxy is for. I read of this method years ago and it was used with the old Smooth-N-Easy epoxy from Hobby-Poxy, which was more or less the same stuff. I haven't tried the SuperFil yet, because I can't buy it at the hobby shop, and I always have some of the Finish Cure stuff around. If I'm fiber glassing something, and strength important I use the finish cure for that also.

I think this stuff sands better because it is mostly micro balloons when it has cured. A side benefit is that I have NEVER had paint lift off of these fillets. I don't know the chemical reason why but even unprimed this stuff loves paint and it just bonds really well. And if it's going to have an iron on covering for the wings, I over lap the covering about 1/4" with the fillet.

So the answer to your quest is the Bob Smith Finish Cure 20 Minute Epoxy.

Type at you later,
Dan McEntee

Avaiojet · « **Reply #17 on:** April 02, 2020, 09:42:41 AM »

Quote from: Steve Dwyer on April 02, 2020, 07:25:15 AM

Charles,

Exactly what is the brand epoxy you are using that allows sanding?

I only use epoxy and micro balloons for the fillets where the wing and control surfaces meet the fuse.
I have used the masking technique you describe and I often use Naptha to smooth the edges to eliminate a step in the event the remaining thickness was too much. Acetone is too aggressive and tends to remove the prime coat of Butyrate sealer.
I typically use the 30 min Bob Smith brand adding the balloons the get the proper stiffness so the mix retains the shape fillet I want. Normally I do the top and bottom areas separately to reduce the chance of movement before curing takes hold.
I always apply a clear Butyrate mix to seal all the balsa before doing anything including silking the wing or epoxying the fillets.
The results are beautiful and even though I've learned to minimize the size (width and thickness) of the fillets I realize I'm adding undesirable weight.
I am leaning toward using Polyfiber Suerfill that many have recommended. It is light and sandable.

My results using the Bob Smith Epoxy adds weight and does not sand. The epoxy hardens to a smooth non-sandable finish. I have also tried the 5 min BS Epoxy with the same non-sandable results.

What product are you using that allows easy sanding?

Steve

Steve,

Go over to CFC Graphic's vendor's corner and view the GBR-3 Build Thread.

I never sand my fillets at the wing root. I apply the stuff as dry as I can with a Starbuck's coffee stick then wipe it with my finger. Done!! Nothing wrong with this.
As far as brand, I only use Hobby Shop grade, and there are reasons for this.

The dryer the mix the easier it is to sand, if sanding is needed and the quicker it dries.

Check out the GBR-3 Build and send me a PM when you get there.

Charles

Steve Dwyer · « **Reply #18 on:** April 02, 2020, 12:02:47 PM »

Quote from: Dan McEntee on April 02, 2020, 08:07:56 AM

Steve;
When making fillets, I use the Bob Smith Finish Cure Epoxy and micro balloons. It's a different mix of epoxy. I add enough micro balloons to the mix to get it to like cake icing or a bit thicker, then apply with my favorite tools and methods. When you add anything to an epoxy mix, it slows down the curing time greatly. The 20 minute handling time can become 2 to 3 hours or more. You don't need to mix a lot of epoxy, because you add so much micro balloons that you usually have plenty for a wing or tail surfaces. I think I mix about 1/4 ounce of each, then the rest in micro balloons and it fill up one of those little graduated mixing cups.When I have the fillet looking like I want it, I wait a while for it to start kicking, and I did my finger in alcohol and drag out the edges. I almost never need to sand them, but if I do, they sand fairly easy because that is what the finish cure epoxy is for. I read of this method years ago and it was used with the old Smooth-N-Easy epoxy from Hobby-Poxy, which was more or less the same stuff. I haven't tried the SuperFil yet, because I can't buy it at the hobby shop, and I always have some of the Finish Cure stuff around. If I'm fiber glassing something, and strength important I use the finish cure for that also.

That explains it I've been using the wrong product. I will try the Bob Smith Finish Cure with balloons.

Thanks for the help.

Steve

I think this stuff sands better because it is mostly micro balloons when it has cured. A side benefit is that I have NEVER had paint lift off of these fillets. I don't know the chemical reason why but even unprimed this stuff loves paint and it just bonds really well. And if it's going to have an iron on covering for the wings, I over lap the covering about 1/4" with the fillet.

So the answer to your quest is the Bob Smith Finish Cure 20 Minute Epoxy.

Type at you later,
Dan McEntee

Steve Dwyer · « **Reply #19 on:** April 02, 2020, 12:05:58 PM »

Quote from: Avaiojet on April 02, 2020, 09:42:41 AM

Steve,

Go over to CFC Graphic's vendor's corner and view the GBR-3 Build Thread.

I never sand my fillets at the wing root. I apply the stuff as dry as I can with a Starbuck's coffee stick then wipe it with my finger. Done!! Nothing wrong with this.
As far as brand, I only use Hobby Shop grade, and there are reasons for this.

The dryer the mix the easier it is to sand, if sanding is needed and the quicker it dries.

Charles,

I saw your PM and I will check out the GBR-3 Build Thread and contact you.

Thanks,

Steve

Check out the GBR-3 Build and send me a PM when you get there.

Charles

Steve Dwyer · « **Reply #20 on:** April 03, 2020, 07:48:11 AM »

Quote from: Avaiojet on April 02, 2020, 09:42:41 AM

Steve,

Go over to CFC Graphic's vendor's corner and view the GBR-3 Build Thread.

I never sand my fillets at the wing root. I apply the stuff as dry as I can with a Starbuck's coffee stick then wipe it with my finger. Done!! Nothing wrong with this.
As far as brand, I only use Hobby Shop grade, and there are reasons for this.

The dryer the mix the easier it is to sand, if sanding is needed and the quicker it dries.

Check out the GBR-3 Build and send me a PM when you get there.

Charles

Charles, I have looked over the fillet work photos on the GBR3 very nice.

I'm comfortable and confident making decent looking fillets from experience using the 30 min slow cure epoxy, see attached shots of a fillet on my Fancherized Twister.

Looking closely you can see the small residual overage line left after spreading the epoxy. It is this detail I have been unable to easily sand away. Now that I am turned on to the BS Finish Cure Product I should have little problem if it sands as easily as you say.

Steve

Avaiojet · « **Reply #21 on:** April 03, 2020, 10:05:07 AM »

Quote from: Steve Dwyer on April 03, 2020, 07:48:11 AM

Charles, I have looked over the fillet work photos on the GBR3 very nice.

I'm comfortable and confident making decent looking fillets from experience using the 30 min slow cure epoxy, see attached shots of a fillet on my Fancherized Twister.

Looking closely you can see the small residual overage line left after spreading the epoxy. It is this detail I have been unable to easily sand away. Now that I am turned on to the BS Finish Cure Product I should have little problem if it sands as easily as you say.

Steve

Steve,

From what I can see, it Looks like you have great building skills.

I flew an Electric Twister a month or so ago before China delivered this to our door. You'll have a good deal of fun with your Twister, I'm sure.

I see that line. Tape line? Using tape is fine, but I no longer use tape, when I did I removed it early to run down the edge with my finger.

If that thin line is difficult to sand, you had a wet mix, much wetter than what's needed. It's miniscule but you can see it. Tape each side and sand it or you can chip it out.

BTW. Does that pushrod exit piece have to be that large? You could tone it down a bit depending on how thick the wood is. That'll get rid of the line.

I know nothing about BS finishing products. I believe I buy his NVAs.

Got a scheme in mind yet?

Steve Dwyer · « **Reply #22 on:** April 04, 2020, 07:03:04 AM »

Charles,

Remember I used Bob Smith 30 min epoxy which is very difficult to sand, even the thin line of residue is nearly impossible to remove. I'm looking forward to trying the alternate product Dan has recommended before I move on to using superfill once and for all.

Regarding the exit faring over the pushrod hole, yes it is a little longer/larger than I would have liked. There wasn't much alternative other than leaving the slot opening exposed. The piece covers the length of the slot and must be the height to allow the rod to clear when the clevis is attached to the flap horn. I dremeled out the piece to 1/16" thick and CA'd the interior for strength. Designer's Choice, I'm happy with it.

Thanks,

Steve

Dan McEntee · « **Reply #23 on:** April 04, 2020, 07:33:15 AM »

Quote from: Steve Dwyer on April 04, 2020, 07:03:04 AM

Charles,

Remember I used Bob Smith 30 min epoxy which is very difficult to sand, even the thin line of residue is nearly impossible to remove. I'm looking forward to trying the alternate product Dan has recommended before I move on to using superfill once and for all.

Regarding the exit faring over the pushrod hole, yes it is a little longer/larger than I would have liked. There wasn't much alternative other than leaving the slot opening exposed. The piece covers the length of the slot and must be the height to allow the rod to clear when the clevis is attached to the flap horn. I dremeled out the piece to 1/16" thick and CA'd the interior for strength. Designer's Choice, I'm happy with it.

Thanks,

Steve

Steve;
When you get a chance to try the Finish Cure epoxy, apply it just like you have been. When the stuff in the mixing cup starts to get thick and cure, dip your finger in some alcohol and drag it carefully along the edges to flatten out that edge. if you do it too soon you can disturb the fillet. When done correctly it will be as smooth as a baby's butt. When completely cured you can then touch up with sandpaper if you think you need to. Keep us posted when you do.
Type at you later,
Dan McEntee

FLOYD CARTER · « **Reply #24 on:** April 05, 2020, 04:17:22 PM »

If you are concerned about any epoxy-type stuff being too heavy for big fillets, like wing/fuselage. why not try leather fillets? They are still available and are easy to apply. All types of dope, paint sticks to the leather. I apply the leather dry with SIG model glue, then wet them slightly to shape them into a more concave shape. The leather edges disappear with a few coats of dope. Do a search for "leather fillets" for suppliers.

Steve Dwyer · « **Reply #25 on:** April 06, 2020, 08:54:25 AM »

Ok, Mr. Carter, I've waited in the wings since yesterday hoping someone would step up with a response to your leather fillet post. No such luck so here I go ready for abuse and embarrassment.

I did as you suggested poked around a bit and found some information on using leather fillets for model airplanes but not much.

Pleeeeease "fillet me in" how are leather strips used as fillets along the wing and the fuse? Have I fallen hard for a belated April Fools folly?

I'm old but always learning that's why I listen to guys.

Steve

Dan McEntee · « **Reply #26 on:** April 06, 2020, 09:46:59 PM »

Leather fillets are an option Ty Marcucci is one that I know uses them a lot. I have a stock of the stuff but haven't tried it yet. There have been some discussions on here about the proper way to apply them. Mainly using a good glue like Ambroid , Duco or SIGment, proper use of pins to hold it in place, and I think to dampen them with water before applying. Finish cure epoxy and micro balloons is quite light. You'll see when you get a cup full mixed up.
Hey TY!!
You're up to bat here!
Type at you later

Steve Dwyer · « **Reply #27 on:** April 07, 2020, 08:20:04 AM »

Come on Ty or Floyd, it's only a "swing and a miss"...........pictures are worth a thousand words. Does leather come in different thicknesses? Seriously you have our attention here.

Steve

John Leidle · « **Reply #28 on:** April 07, 2020, 09:45:58 AM »

Always wondered what leather is used... like a tongue from my old work boots ?
John

Dan McEntee · « **Reply #29 on:** April 07, 2020, 09:51:14 AM »

leather fillets do come in different sizes and the stuff I got tends to look like baseball glove material.It's original use is for making sand casting molds and other tool and die work, and is still made. There was a gentleman who produced kits, whose name I can't think of, who offered the material also is several sizes. He unfortunately passed away, and his daughter was selling off his stock of kits and fillet material, and that is where I got mine. That has been several years ago, Ty will tell you where he gets his when he chimes in or you can search out the thread, but it is a pattern maker supply place. Kind of a lost machine shop art in this day and age but is still done in some places.
Type at you later,
Dan McEntee

Jack Pitcher · « **Reply #30 on:** April 14, 2020, 11:11:29 AM »

A internet search for leather fillet suppliers turned up a couple of hits. In addition to Freeman Supply (100' minimum, didn't ask for a quote) also found filletexpress.com where shorter lengths can ordered.

Jack