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Casting with Clear Resin

Posted:
Fri Aug 21, 2015 8:06 pm
by Nor Cal Mike
Anyone done any casting with clear resin? I am thinking of trying my hand at resin casting this winter and want to start simple My biggest need are clear parts for the vintage Strombecker roadsters and the like. I would love to have a source for light lenses and windscreens. I would imaging that casting without bubbles might be the tricky part. Has anyone done anything like this? What say yee?
Re: Casting with Clear Resin

Posted:
Fri Aug 21, 2015 8:23 pm
by mattb
Mike, I've made several attempts. The last was with the Alumilite clear which worked best of all I tried. Without vacuum and pressure it is nearly impossible to not have air bubbles. I made a decent piece every now and then, but it was like 1 in 10. Midget racer and small stuff came out better then bigger items like 1/24 windshields. The best stuff I made still had minute air bubbles but looked good enough for me to use.
I found it best to use the resin in a couple days or a week and not let it set around after opening. It tends to absorb air pretty fast. The mixing must be 100% perfect, there is no margin for error like with colored resin.
I don't mean to discourage you, give it a shot and see what you can do.. The best source for replacement clear lens and stuff still seems to be old 2 litre bottles and other clear plastic containers!
Re: Casting with Clear Resin

Posted:
Fri Aug 21, 2015 10:03 pm
by munter
I cast using clear resin and as mattb says the air bubbles will drive you to distraction. They mostly get in during mixing so if you want to experiment with mixing techniques that don't drag air into the stuff then you will have better results.
Best results for me have been by degassing the mixture in a vacuum chamber...I have done some screens with marginal success and a few headlight lenses with better/ good results.
Little parts are always tricky, trickier than big parts.
Here the stuff is expensive and slow to cure....air temp seems to make a difference.
Re: Casting with Clear Resin

Posted:
Fri Aug 21, 2015 10:42 pm
by Nor Cal Mike
Thanks for the inputs gentlemen. I can deal with windscreens using soda bottles or by carving a buck to make vacuform glass. Never mind that I haven't built a vacu box for that purpose but I am close and they aren't too complicated. I did carve a buck that I sent to our good friend Bob Taylor who knocked out some windscreens for our resin repops of Tipo 61 birdcages. I think that buck produced some pretty fine looking glass for those cars. But those little headlight lenses fickle me. I can't see cutting out some little fingernail sized pieces of thin plastic soda pop bottle that will stay in the car during the usual bumping and banging of slot car racing. That I am building these classic roadsters for digital racing compounds only that problem. I wouldn't mind air bubbles in a headlight bucket like I would a windscreen. But if this stuff doesn't last long once the can is opened, I'd better be ready to pour a whole heck of a lot of headlights once the can is uncorked. Maybe I will have to rethink this idea. But I still want clear lights. Thanks again for your inputs.
Re: Casting with Clear Resin

Posted:
Sat Aug 22, 2015 12:32 am
by munter
I have made lights by using a punched out circle of aluminium and a carefully placed blob of araldite/two part epoxy glue.
Re: Casting with Clear Resin

Posted:
Sat Aug 22, 2015 10:39 am
by Nor Cal Mike
Re: Casting with Clear Resin

Posted:
Sat Aug 22, 2015 2:20 pm
by munter
Sorry for my misinformed input. I was thinking the light lense but I see you were talking about what I call the lense cover.
I vac form the covers and cast the lenses, usually.
Re: Casting with Clear Resin

Posted:
Sat Aug 22, 2015 2:42 pm
by Nor Cal Mike
Perhaps you were misled by my poor terminology. These are what I mostly need, the stronger the better for digital racing.
Re: Casting with Clear Resin

Posted:
Sat Aug 22, 2015 5:07 pm
by chris
Would the guys who do the vac. formed bodies like Pattos in Australia and Betta in the U.K. have what you need?
If so, you simply cut it up for the parts required, could save time.
Chris
Re: Casting with Clear Resin

Posted:
Sat Aug 22, 2015 6:07 pm
by Nor Cal Mike
I'd hate to pay the prices for those complete bodies plus shipping for only the clear parts that could be cut from them. I have too many of these incomplete Strombecker bodies that I want to do. I think the key for this being economically justifiable is to be able to produce the parts here at home. I do have a couple of vacuform windscreens for the TR250 that a nice friend was kind enough to make for me. Thanks Chappy! These were taken from his Ninco TR250. The upper deck is flatter on the Strommy version but they actually fit pretty decent if you turn them upside down. I now have a complete Lionel version of both the TR and the J Type body with windscreens intact. It looks like Lionel must have used some of the Strombecker tooling because though not identical in a few details, they are strikingly very similar otherwise. I can make a clay mold from these screens for transforming into a vacu buck. Over the winter, I plan to make a silicon mold with both the J Type and the TR light covers shape imbedded. I will try the clear polyester resin at first. If it works and looks at least as good as the originals in the picture above, my problem will be solved and I will have the ability to make parts to share with others who are playing with the same toys as I.
Re: Casting with Clear Resin

Posted:
Sun Aug 23, 2015 1:28 pm
by Ky.Slot Racer
Mike I`ve done the clear also, and my bit of experience says it isn`t worth the effort for your small needs. I would suggest using bare metal foil, or bare metal aluminum as a background inside the cavity. Then just drip some Future until you have the level you want and let dry.
Re: Casting with Clear Resin

Posted:
Sun Aug 23, 2015 3:24 pm
by btaylor
Mike, I have a TR here that I am willing to sacrifice to make a vac mold. It would mean cutting off the front fenders, and using them for a buck. We would still have to trim them out of the vac sheet, but they would be as close to O.E.M As possible.
Bob
Re: Casting with Clear Resin

Posted:
Sun Aug 23, 2015 5:37 pm
by Nor Cal Mike
Re: Casting with Clear Resin

Posted:
Sun Aug 23, 2015 6:20 pm
by chappy
Hi guys, if you are talking about the clear lenses for the headlights, it can be done 2 ways.
Depending on the size of the vac machine. Some resin makers use a complete front section with light lenses and vac over it to get duplication. If a small vac machine I used clay to make the buck of the actual lense shape, by filling the headlamp cavity to the requiredshape. Once air dryed remove from the
cavity and vac form , I always add a bit to the bottom to have it sit proud, and then trim down.
I dont mind doing them if you want to send me the bodies or parts, and I can make masters aswell for any future needs.
Hope this is a bit helpful.
Bob
Re: Casting with Clear Resin

Posted:
Sun Aug 23, 2015 9:31 pm
by chappy
By the way I also use a pressure pot on resins, but it is only a paint pressure pot for spraying, and you can set the pressure at about 25 psi which seems to, work well.
imthinkmi oaid 65 Cdn so I imaginenits less down there. Just take out the suction tube that goes down in for the paint and you end up with a pot larger than a gallon can. You cannuse it upright for small stuff or on its side for longer stuff.
Works pretty well too.
Bob