Ways to avoid runs on epoxy fillets

[Karl]

Could someone please tell me how I can avoid my fin fillets from runing? I've tried sticking a small dia tube in the fillet and dragging it down to remove some of the epoxy & to form the shape but when I get back to it when it's dry theres always a small blob at the bottom where the epoxy has built up

 

[lalligood]

There are fillers that you can add to thicken the epoxy.

My favorite is milled fiber (tiny, chopped up pieces of glass). It adds strength as well as gives epoxy a peanut butter consistency. Forget about sanding the stuff though. It's hard as a rock!

Microballoons don't take away from epoxy's strength but IS easier to sand.

Wood fiber is another one.

I'm sure other folks will chime in with more...
HTH,

 

[hokkyokusei]

I use this stuff:
https://www.cfsnet.co.uk/acatalog/Low_Density_Filler.html
Makes the fillets easier to sand too.

 

[Karl]

Ahh you use CFS too hokk? I've had their catalouge for a while now. Looks like im gonna order some Glass Microspheres & Milled Fibre (BSD) from deepsky

But I did get some 'Double Bubble' epoxy from Dbarrm , and it comes in a little sachet , and when mixed it turns into the peanut butter consistency that you were talking about . But I carnt find a trace of the stuff here in the UK! Theres tons of different verietys aswell , stuff for metal , wood , plastic , glass , everything! And all in different speeds!
Karl

 

[Karl]

Ohh , I've just been looking at what Milled Fibre is , and I have some Fiberglass Matting left over , could I just chop that up with a blade into fine pieces and blend it into epoxy?
Karl

 

[hokkyokusei]

Originally posted by Karl
Ahh you use CFS too hokk? I've had their catalouge for a while now.

Yeah. Good range, lots of accessories, friendly on the phone, open minded[1], reasonably priced, quick delivery...


[1] What I mean by that is that even though they are basically boat chandlers and not rocketry vendors, they are "rocket friendly". When you tell them what your using it for they don't go "whaaaaat!".

 

[DynaSoar]

Originally posted by Karl
Could someone please tell me how I can avoid my fin fillets from runing? I've tried sticking a small dia tube in the fillet and dragging it down to remove some of the epoxy & to form the shape but when I get back to it when it's dry theres always a small blob at the bottom where the epoxy has built up

Fingertips to smooth it, paper towel to wipe what dribbles, paper towel with alcohol to clean the tube where the dribble was wiped and to clean the fingertips.

When you pour them, don't pour all the way to the ends. When you smooth it, smooth it fore and aft to the ends. Then you'll have very little dribble. Also, tipping the bird to let it run to the ends reduces the amount of finger application.

Also, you can put a fillet over a fillet. Fast cure is easier to work. If you're using slow cure, use only enough for the strength, then cover it with fast cure. Actually, I only use fast cure, and the few goofs I have I can cover easily with a little more, after it's set.

I should probably include a Standard Disclaimer about using rubber gloves because epoxy on the skin is a Bad Thing, but I don't and it hasn't affected me flibbet VOOT snah snah snah POIT spabit one bit.

 

[Stymye]

Could someone please tell me how I can avoid my fin fillets from runing

add a thickener, or microballoons if you want it to be sandable
check the hobby shop, NHP brand phenolic Microballoons shouldn't be hard to find. or mix a combination of the 2

as far as not protecting your skin,, it's not IF you will have a reaction but ,WHEN ..I'm sure some people are more resiliant than others
but when you do begin to see the effects , it's all downhill from there, not worth it. gloves are cheap.
and wiping your skin with alcohol absorbs it in even quicker.
(double whammy)

fibers are not thickeners, they are strengtheners

and microballoons Do weaken the mix(it's full of hollow spheres !)...

posting both miss-information and unsafe practices...c'mon guys