Apparently I am in search of the perfect fillet tool. Beyond the normal plastic scraper that epoxy sellers carry - good but after several uses get rough and don't give you perfectly smooth fillets without additional reworking, I have tried a racketball ball- works well to shape but not spread and hard to hold and a sculptor's rubber shaping tool - excellent but asymmetrical shape needs to be kept in mind. My latest acquisition, a silicone basting spoon - perfect curve, symmetrical, flexible, concave and convex surfaces and spoon shape for excess fillet epoxy mix holds great promise. I sawed off the handle today but did not get a chance to use it. Perhaps tomorrow and if not tomorrow then certainly Monday! Will I find my own personal fillet nirvana? I will report back!
posted by tsunamichaser at 6:59 PM
3 Comments:
For many years I had (until recently) a tool for making plasticene fillets in my patternmaking (I work in fibreglass). It was a pushrod from a locally built engine (Holden) which had a hemispherical end and a larger cup on the other. I welded a steel ball to this cup and then had two sized fillet makers in the one tool.
It was excellent (must make another!). It was a constant shape no matter what angle it was on. It could be pushed as well as pulled. Quite a lot of pressure could be applied to "cut off" the fillet cleanly on the edges because it wouldn't distort and left very smooth fillets. Easy to clean too although I wasn't using it with epoxy.
Fillets made with talc thickened resin will be smoother than those made with microballoons. A mixture works well, too.
Talc can be bought here in Oz from fibreglass supply houses in 25kg bags at aout 0.50c a kg. It is reasonably heavy and harder to sand but if the fillets are well formed then thae sanding isn't an issue and a slightly smaller fillet will overcome the weight. This is possible because talc bog is much stronger than microballoon bog (or gunk as we call it).
I trick I have read about but haven't used is to brush the epoxy fillets with a little resin when they are cheesy.
BTW, your woodwork looks superb!
I like both of your comments Jim. The idea of using an engine valve rod is great as is the welded on ball bearing. Let me try the spoon first. In the meantime I'll hunt for the right sized ball bearing and an old valve to use. What often is the problem is clean up of the epoxy tools after use. With a tool made of metal you can use a wire wheel to clean it up.
I use your trick of coating the fillet with straight resin. That works well! I'm playing around with my "prepreg" cloth too in that I add it to an uncured fillet, lay thick clear plastic over it and smooth it until it is what I want. Then I let it cure and peel the plastic off.
The fillet material i use is a premix. I believe SystemThree makes it with wood flour. I add wood flour to this mix sometimes to make it even thicke ror mix my own batches.
Post a Comment
<< Home