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japcas
04-19-2006, 08:11 PM
Hello. Some of you may remember the pictures I posted earlier of the Pioneer model engine I have been building by Rudy Kouhopt. Anyway, I have been trying to repaint the flywheel and I'm having mixed results. I painted the outer rim silver and the spokes and hubs black. I first painted it with an airbrush with thinned testors enamel. I like the finish of the silver but the problem comes when I try to mask it to paint the black. I having been using some normal masking tape but it seems to want to pull a fine layer of paint off with it and it leaves a slight sticky residue on the part. I decided to repaint it with some cheap spray can paint from walmart. Same thing, nice finish but after masking the silver looks like crap. Would I be better off spraying the silver and brush painting the black because I believe I could paint it without masking? Am I doing something wrong, is the paint not right for the job or is my masking tape the blame? I am open to any suggestions which will help me get a better finish. By the way, the metal is cast iron and I have been cleaning the part before painting with denatured alcohol.

black powder
04-19-2006, 08:54 PM
Are you scuffing the metal (sanding)to give the paint something to adhear to,
are you priming befor you paint?

PHiers
04-19-2006, 09:06 PM
You may want to try the masking tape made for painters. I bought some a couple of years ago and it seems to strip off clean. I think regular masking tape tends to stick too tight.

I don't remember where I bought mine but since it came 6 rolls to the pack I am betting enco, grizzly, or maybe wholesale tools.

CCWKen
04-19-2006, 09:10 PM
I bet it's not an adheasion problem. It's the type of silver enamel. The aluminum particles come to the top because of the carrier used. It acts like a surfectant to "float" the particles. These types of paints don't take to taping because the tape removes the alumimum (shinny) layer. It's also the reason you can wipe it and get silver on your finger.

You might try using an epoxy silver or polish the wheel and spray it clear using a gloss or semi-gloss.

japcas
04-19-2006, 09:42 PM
Thanks for the help guys. I don't believe it is an adhesion problem. Just a light layer comes off like Ken says. If it was a steel flywheel I would polish it and clear it but it's cast iron. If there is a way to get cast polished let me know but I've only been able to get a dark grey out of the stuff I've worked on. And PHiers, I agree. I believe this type of tape is actually to strong for this kind of work but I just can't seem to find any I like at the hobby shop. I may have to run down there tomorrow and see if they have anything new. CCWKen, do you think I could paint the silver, then clear it and then be able to mask over it satisfactorily with out messing up the finish? I would just paint the black first but because of the flat sides of the flywheel it is much easier to get tape on the silver part then trying to mask off the spoked area.

JCHannum
04-19-2006, 10:12 PM
Cast iron will polish up nicely. Just chuck the wheel up in the lathe and use progressively finer grades of emery cloth backed up with a file to polish.

You can get down to about 320 grit with emery, and go on to wet or dry paper after that. I use WD40 to wet the emery or W/D paper.

It is an engine model, and polished steel or cast iron is more authentic and looks better than aluminum paint will, and it will hold up much longer.

This is my Eclipse, with polished flywheel rims. I only went to 320 grit on this, you can get a mirror finish if that's what you are looking for.

http://members.aol.com/jchannum/eclipse

CCWKen
04-19-2006, 10:18 PM
The clear will will just turn the silver to a grey color. The solvents in the clear break down the adheasion layer between the base and the aluminum layer so the base/carrier comes to the top instead of the aluminum. It won't be an even-looking grey/silver either.

I've polished cast iron to an almost chrome look but what you have is probably what is called grey iron. I've never tried to polish that but if the surface finish is fine enough, you should be able to polish it too. You'll need a polishing wheel and some compound. Doing it by hand would take forever.

CCWKen
04-19-2006, 10:23 PM
Ops, there you go! JC shows a good example.

Mcgyver
04-19-2006, 11:12 PM
It is an engine model, and polished steel or cast iron is more authentic

JC, did those early engines, hit and miss etc, have polished flywheels? The only only old engines I see are at fair grounds etc, and they never seem to be polished, made sense as i figured it wasn't appropriate as they were work horses.

Authenticity is what I want a model to be and I always thought pics of these engines with polished flywheels were not authentic, kind of like a car guy chroming various parts, nothing wrong with that it that's you're thing, but I just never thought of it as authentic. now you're making me wonder if i'm missing something...did the old timers used to polish these like train engineers on the valves & con rods?

engine looks good - is that a recent pic ?

JCHannum
04-19-2006, 11:48 PM
Mcgyver, Thanks, I got the engine running in the fall. I hope to paint it this summer when I can leave it outside to dry.

The original engines were work engines, and for the most part saw farm duty. The flywheels were probably painted with the same thick paint used on the rest of the engine. At the shows, you sometimes see them polished or even chromed, but they were originally more utilitarian in appearance.

Models look prettier with a nice paint job and polished brass and steel parts, so we can take a bit of a license with them.

I won't go much farther with the polishing than this, and since I am lazy, it will eventually develop a nice patina and look more authentic.

big-dipper
04-20-2006, 04:05 AM
The painter's masking tape, all the stuff I have seen is blue, is available at any Menards, Home Depot, Lowes, True value around here.

japcas
04-20-2006, 10:16 AM
Thanks JC, that's just what I was looking for. I have never polished long on cast iron but I would have never thought it could get that bright but I have been to shows and seen them that way. My flywheel came from Martin Model. Guess I'm down to the lathe to get set up to do a little polishing. I know it will be more durable than the paint. Ken, you might be right also, it may be greay iron but I will see and post some pics when I get her done. Thanks again guys. :)

Scottike
04-20-2006, 12:40 PM
To mask off a freshly painted area sprinkle your tape with a light dusting of talcum or baby powder. It won't stick quite as well, but it won't pull paint (as badly) when it's removed.

Tinkerer
04-20-2006, 02:09 PM
To strike a line of tape on a freshly painted panel ( dry but still green ) without having the layer lift. Lightly drag the length of tape over your pants leg this will temper the tack and aid in removal. For a smooth feathered edge lift the tape while the paint is still wet... the edge will feather out and flatten. To aid in removal of tape dog ear the none paint edge at the ends or place a double backed piece of tape about a inch long under half the tapes width at the ends as a pull tab to lift. For a finer edge line use scotch tape instead of masking.

RPease
04-20-2006, 02:32 PM
japcas..........After you paint the rim (and after it dries), just put a light coat of vaseline on the rim, then air brush or spray the spokes.

The paint won't stick to the vaseline and you can wipe it off after the spokes dry. It shouldn't affect the silver paint, but I guess it really depends on what kind of paint your using. Just don't "glob it all over the edges" and you shouldn't have a problem with interfereing with the spoke paint.

I presume that your using some kind of mandral to hold the flywheel so that you can work with it.

Regards..........Rodg

japcas
04-20-2006, 06:04 PM
Thanks again guys for all the great replies. The tape over the leg trick sounds painful as I usually wear shorts when working in the shop.:D I had actually thought about trying some vaseline or some kind of grease to use as a masking agent. I believe I will try to polish it as JC said.

Samuel
04-21-2006, 01:34 AM
another product that I dont think I saw mentioned was a product called " friskit" it is designed for use by airbrush artists. it is a plastic film that you can order in solvent resistant form ( water resistant is also offered for use with water colors and acrylic paints ) and also with different levels of " tack" and thickness. the difference between masking tape and friskit is that the masking tape actually has some sort of gum where as the friskit is more like thick super saran wrap , slightly tacky, but not sticky. just enough to hold it down, the other nice part about friskit is that its clear, so you can see if there is any break in the seal at its edge that would normally let paint uder it . helps in placing and cutting as well.



Samuel

japcas
04-28-2006, 10:56 PM
Thought I would take a minute to post a picture of my engine after I finished polishing the flywheel this morning. It didn't take too long at all. I stopped after 600 grit as I was plenty happy with the results I achieved. The engine by the way is the Pioneer engine that Rudy Kouhopt designed I believe in 2003. It's a two stroke non compression engine with poppet valves. It has a 1.125 bore and 1.5 inch stroke. This is my first engine and now I am going to start on a 1/4 scale 5hp Galloway that I bought at the NAMES show last weekend.

http://i32.photobucket.com/albums/d39/japcas/PICT4928.jpg

speedsport
04-28-2006, 11:18 PM
You would get the results you desire if you would buy some quality automotive paint.

AllanD
04-29-2006, 11:07 PM
The engine by the way is the Pioneer engine that Rudy Kouhopt designed I believe in 2003. It's a two stroke non compression engine with poppet valves. It has a 1.125 bore and 1.5 inch stroke.

Gorgeous engine. Have you had it running yet? I've been eyeing this one for for a while now as my first IC engine project.

Allan

Schutzhund
04-30-2006, 06:04 AM
That came out great!

For future reference try a tube of white lithium grease for masking. I get excellent results with it. You can mask very small areas by applying it with a toothpick.

Same principle as Vaseline I guess, but I find white lithium easier to see as Im working.

japcas
04-30-2006, 11:27 AM
Gorgeous engine. Have you had it running yet? I've been eyeing this one for for a while now as my first IC engine project.

Thanks Allan for the compliments. Yes I have had it running but not as well as I would like for it too. I have been having trouble with it wanting to 4 cycle and the motor is a 2 cycle. I know that this is usually caused by running too rich but I can't seem to get an extended run out of it when I start to lean out the mixture. I have been thinking of trying a buzz coil ignition if I don't get it going to see if that would help. One last thing, it may not be completely broken in yet so I am trying to be patient and just run it when I can and see if it gets better with time. By the way, I think this would make an excellent first model for someone wanting to build an ic engine because it is made out of mostly scrap stock. I did buy the flywheel from Martin models just because I like the look of the curved spoke flywheels.

AllanD
04-30-2006, 08:28 PM
Thanks Allan for the compliments. Yes I have had it running but not as well as I would like for it too. I have been having trouble with it wanting to 4 cycle and the motor is a 2 cycle. I know that this is usually caused by running too rich but I can't seem to get an extended run out of it when I start to lean out the mixture. I have been thinking of trying a buzz coil ignition if I don't get it going to see if that would help. One last thing, it may not be completely broken in yet so I am trying to be patient and just run it when I can and see if it gets better with time. By the way, I think this would make an excellent first model for someone wanting to build an ic engine because it is made out of mostly scrap stock. I did buy the flywheel from Martin models just because I like the look of the curved spoke flywheels.

Great info japcas, thanks. I'm sure it'll run better and better as it gets broken in. Your project completion has knudged me into starting mine.

Take care,
Allan

laddy
04-30-2006, 08:58 PM
Hey,
I have had an eye on buying the plans as well. Are they straight forward and clear? Any real tricky stuff? Is it doable on a 6 inch lathe? Thanks, yours looks really GREAT!!! Fred

japcas
04-30-2006, 11:27 PM
Hey,
I have had an eye on buying the plans as well. Are they straight forward and clear? Any real tricky stuff? Is it doable on a 6 inch lathe? Thanks, yours looks really GREAT!!! Fred

Hello Laddy. I thought that the plans were very good and there is some build tips with them. I done all of the big lathe work on my 9x20 lathe but later on I decided I would like to buy a bigger lathe and bought a 13x40 Jet lathe. I wound up finishing all of the small parts on it just because I like it better than the little lathe. It is totally doable on a small lathe with a little patience. One tip, if you guys aren't sure if you would like to build it I would recommend renting the video from TechnicalVideoRental.com. It is a two dvd set and cost me $16.95 to rent if I remember correctly and they send you a set of plans to look at but you have to return them with the video. I believe they let you keep them for 1 or 2 weeks, but I can't remember for sure. I felt like it was a good bargain and in the video Rudy completely assembles an engine and you get to see and hear it run also. I liked it a lot. If you want to buy it I believe it sells for $70 or so with the dvd's from the village press if I'm not mistaken. The rental is a good way to go to help you decide if you would like to build it though in my opinion.