I've been trying to mix up some light weight fillers for my model , with little success .
Does anyone have a good recipe for mixing SIG Micro balloons , to get a nice smooth , yet sandable paste , or filler ?

Rob K.

HI Rob,

What are you needing to fill?  I generally use light weight spackle for slight dings and such.

Rob:

  For fillets and for blending canopies I have just recently started using Sig Epoxolite. As far as I'm concerned it beats Brodaks areopoxy all to heck. It's more user freindly and sands great. I have Micro Balloons but haven't used it yet, so I too would like the formula.

There is a product that I have been meaning to buy from Aircraft Spruce called Super-Fil.
It is a light blue, I understand.  Made for the purpose of fillets and such.  Everyone I have talked to that has used it says it is the best by far.

Randy Powell (IIRC) uses it, maybe he will "fill"us in!

Spackle is about the only thing I've found that applies quickly, dries fast, is sandable, etc... Only bad thing is that sometimes dope doesn't like to stick to it. 

Microballoons work great in epoxy, anything else seems to just make a mess.  The Sig packaging even suggests mixing with Sig-bond which is basically Ambroid, but that just turns into a goop that kicks before its applied. 

Epoxolite is great, except that its messy, takes forever to dry, and is impossible to sand.  Not to mention if you don't rough it up or clean its surface before painting, nothing will stick to it. 

I tried the microwave trick and the gray stuff basically just cooked itself out of the plastic tub.  It was 10 years old though, so it could have just been the age. 

I have used Micro-Fill with pretty good luck let it get hard,sand smooth and hit it with thin Ca works good not messy.  Made by NHP suppose to put thin coat of polyester resin over it before dope will stick to it, or epoxy resin

HI Rob,

Ask away!  That is the primary reason this forum is here. 

As you will find, there about as many ways to skin a cat as there are people skinning them.    Find a technique you are comfprtable with and build on that.

Hi Rob,

Much has been said about fillers, however until you hear from those that have used a product called "super-fil" made by Poly Fiber, you haven't heard it all.  It is easy to mix, 2 parts blue 1 part white and then stir.  It is a soft putty that dries in appx 12-14 hours and then sands like a dream.  Workability?  Scott Riese put me onto it when he did the Fillets on my Ringmaster and all I can say is wow!  I suggest that  you use google and key in Poly Fiber and then at their web site read up on Super-fil.  I purchased mine at Wicks but perhaps there is an outlet nearby where you live.  They have a toll free number and maybe by calling them you would be able to find a source right in you back yard.

Marv

On small dings, I've been using Plastic Wood, the common stuff in hardware stores. The ugly yellow color doesn't blend in much, but it sands well, especially when using a sanding block or t-bar. Under silkspan and primer, the color is hidden. I like the way it sands and the way dope sticks to it. I used light spackle for a while, nice and light, easy to sand. But dope didn't always stick well. At times the silkspan I applied over the solid surface failled to attach. Not a problem with the ugly yellow/orange plastic wood. I've hesitated to use plastic wood as a fillet. Thought it lacked the strength to make a radius and stay put. Thought it might fatigue crack over time. Of course it is possible to make a fillet using the ugly orange yellow paste, and, after it sets up, a top coat of CA or epoxy, might keep the fillet intact. Anyone try that?

Actually, I have used a long needle and syringe to inject a little water into a covered ding from the backside of the sheeting, even from the bottom side of a wing or stab.

The wood usually returns to it's un-dinged state and the needle mark will disappear with a little heat from your covering iron.

Jim Oliver