Dummy engine
 

Hi I'm building a 1/5 scale SIG J3 Cub. I just started working on the cowl and the plastic dummy egine parts. My first question is, can I use Testers enamel to paint the dummy engine parts since they should not have much contact with glow fuel being on the outside of the cowl that far front? and after they are painted what glue should be used to fasten them on? I am planning on painting the fiberglass cowl with SIG Supercoat cub yellow. I am also covering the plane with Cub yellow Solartex

Thanks for any input

RE: Dummy engine
 

You can use Testors paint, but you will still need to fuel-proof the cowl. The propwash will still blow a mist of oil there, not very much at all, but enough to eventually make the paint peel. Try LusreCote clear over the cowl paint. If you let the undercoat cure for a week or so, and LIGHTLY mist the first couple of coats of LustreCote on it should work. A heavy coat over uncured paint can craze the finish, as LustreCote is a lacquer. You can also clearcoat the Solartex, it will fill the weave a bit and make it easier to keep clean. The weight is negligible and the Cub can gain a good bit of weight without problems (mine weighs over ten pounds) Ca will bond the dummy to the cowl, use thick or gel and make a tiny fillet around the edge.

I would also add a layer or two of 1/2 oz. fiberglass cloth inside the cowl, and the "chin" area, where the carburetor air filter is on the full-size, needs even more, as it is the first part to make contact when you nose the plane over (and you WILL, at some point)

This kit was my second plane, and first scale build. How do you like it? It goes together really nicely. What engine are you putting in it, and how will you mount it? Are you building the wire gear, or using a scale aftermarket gear. A true bungee action gear really helps the way it ground handles. If you do use the wire gear, take pains to put just a tad of toe-in into it, and try to keep it even. This will also help the ground handling. Hope your build goes well, post some pics. Ken

RE: Dummy engine
 

so far the build has been alot of fun. I started it the last week of November, everything is framed and ready for Solartex. I ordered the Solartex from my LHS it should be here next week. I built the wire landing gear and I plan on starting with it, but I may upgrade at a later time when I have some extra cash laying around. I'm using a Magnum XL-52RFS 4-stroke, I was told this would be a good motor for this plane, a few of the guys at my flying field use this motor and they all like it

RE: Dummy engine
 

Hi,

I used a combination of Randolphs dope, Krylon and Testors model enamel on the engine area. The Testors, stainless steel, was used on the valve covers.


It has been flying for about a year now and seems to hold up OK. The only problem I had was when a fuel line let go during re-fuel and caused the black Krylon to soften a bit. I plan to put a coat or two of urethane on it this winter. Should be good to go this spring.

RE: Dummy engine
 

The Magnum ought to be a good choice, especially since you haven't let yours get fat like I did :) (I did several mods that added weight, as well as a few crash repairs over the last two years). I've got a .65 Saito in mine, plenty of go even with the weight.

ec121--what engine is in your Cub? Looks like a Saito, but haven't seen one with ribbed valve covers until you get to the 1.20, unless it's one of the much older .50's. Great job on the dummy. I took the 'road less travelled' and made my own dummy, took two weeks of fiddling.

RE: Dummy engine
 

Hi Khodges

This cub is one that i did up for an old flying friend.

It is a 1/4 Sig and the engine is an OS 120. I used the supplied dummy engine so that I could use the eyebrows to duct air to the engine, Other than the eyebrows the only other inlet area are the two small openings on the front of the cowl. The baffels keep the air moving in the right direction.

This one flys in summertime temperatures that are well above 100F on a regular basis. No cooling problems to date.

BTW ..... Your cub looks great. A guy down the road from me is building a cub for his first plane. He told me that he planned to paint it in the WW2 scheme. I sent him your posts and links to the photos of yours.

SeYa ....