little tip for those who want to cast wheels

[Lownslow]

but dont want to deal with 2pc molds or solid wheels.
i dont have the room for 2pc molds and i dont like making 1pc casts of wheels larger than 18" especially with a lot of spoke spacing so i decided to try and just cast the face of the wheel as opposed to destroying the master trying to just get the face of the rim.

i cut a piece of cardstock just enough to slip the wheel in then sealed it with glue. then i build a support box so that the weight of the mold rubber doesnt bow the sides out and the weight doesnt rest on just the wheel. i tried it before with a more barbaric method but the result was succesful.



this was the prototype that inspired the idea


im happy with the result

[countach79]

i don't know a thing about resin casting but that looks cool!

i must try it some time

[Brandon Miller]

Some more pics would help because I am confused as crap on what you did.

[ScaleTuned]

Whats the size of that wheel? You did in fact make a 1 piece mold whether you hacked the master or not. Whats the issue with wheels larger than 18 inch in 1 piece molds? I've done 15's through 21's in the same manner and there is no quality difference whatsoever. Problem you'll have doing it the way you show is that the resin is very thick in the area's between the spokes which makes it a pain to clean them out nicely. 2 piece molds are only slightly thicker than a 1 piece flat mold, otherwise there is no difference.

[Lownslow]

Originally Posted by ScaleTuned

Whats the size of that wheel? You did in fact make a 1 piece mold whether you hacked the master or not. Whats the issue with wheels larger than 18 inch in 1 piece molds? I've done 15's through 21's in the same manner and there is no quality difference whatsoever. Problem you'll have doing it the way you show is that the resin is very thick in the area's between the spokes which makes it a pain to clean them out nicely. 2 piece molds are only slightly thicker than a 1 piece flat mold, otherwise there is no difference.

20" i have but the wheel isnt a solid 1/4" brick should i have casted the whole thing. i tried a 2pc thin mold and i only got 6 sets before it started tearing.

[cinqster]

Sorry Lownslow, but I have read your thread repeatedly and do not know what you are trying to explain!

Can you please explain further - I'm casting 40mm wheel centres which are less than 1mm thick with two piece moulds and have no problems at all!

[ScaleTuned]

Originally Posted by Lownslow

20" i have but the wheel isnt a solid 1/4" brick should i have casted the whole thing. i tried a 2pc thin mold and i only got 6 sets before it started tearing.

I'm not understanding this, sorry. What type of mold rubber are you using? I use Dow Corning HS2 all the time and pull 60-80+ parts no problem no matter 1 piece or 2 piece molds. If your using poor quality RTV that is part of your problem.

If your going to cast wheels in 1 piece flat molds that the back of the wheel has to be flat, which I'm sure you know already. Yes, normally you have to hack a wheel on the backside to make it flat for 1 piece molds, however, not all wheels can be hacked in this manner. On modern large diameter wheels, sometimes the center hub (on the backside) is offset past the "spokes" of the wheel. Meaning if you cut/sand that smooth from the back side you'll damage the center of the wheel, normally the lug area of the front. Wheels such as this can be cast in 2 piece molds w/out any problems at all.

Not sure what you mean about solid 1/4 inch brick. The method you used will definitely make the area between "spokes" thicker and much harder to remove. Thats obvious from looking at your last picture.

[ScaleTuned]

Originally Posted by cinqster

Sorry Lownslow, but I have read your thread repeatedly and do not know what you are trying to explain!

Can you please explain further - I'm casting 40mm wheel centres which are less than 1mm thick with two piece moulds and have no problems at all!

I believe what he is trying to show is that he doesn't want to cut/sand the back side of his master flat for 1 piece casting. So he built a platform and only protruded the wheel maybe 1/8 inch to pour his mold rubber on top of. Again, problem with this is, the area between the spokes which has to be removed will be nearly as thick as the wheel itself and be a total pain to remove. If the wheel is flat cast in a 1 piece mold the area between the spokes is paper thin and removes cleanly with little effort.

[Brandon Miller]

And why was my post deleted? All I asked for was more pics to further explain what he was doing.

[stryfe101]

That's a pretty good idea, I did the same thing with the salt flat specials I cast from the 57 Chevy wheels of fire kit, haven't thought of it with other wheels though...hmm...

[cinqster]

Originally Posted by ScaleTuned

I believe what he is trying to show is that he doesn't want to cut/sand the back side of his master flat for 1 piece casting. So he built a platform and only protruded the wheel maybe 1/8 inch to pour his mold rubber on top of. Again, problem with this is, the area between the spokes which has to be removed will be nearly as thick as the wheel itself and be a total pain to remove. If the wheel is flat cast in a 1 piece mold the area between the spokes is paper thin and removes cleanly with little effort.

Cheers ScaleTuned, now I'm with it! I think it was the 'don't have room for 2 pc molds' that lost me! Still not sure why someone would go this route, it's almost as much hassle as doing a decent two piece mould but not as good!

[Lownslow]

Originally Posted by ScaleTuned

I believe what he is trying to show is that he doesn't want to cut/sand the back side of his master flat for 1 piece casting. So he built a platform and only protruded the wheel maybe 1/8 inch to pour his mold rubber on top of. Again, problem with this is, the area between the spokes which has to be removed will be nearly as thick as the wheel itself and be a total pain to remove. If the wheel is flat cast in a 1 piece mold the area between the spokes is paper thin and removes cleanly with little effort.

havent had a problem since i started

[drunken monkey]

i also don't see what advantages this has over making a good two piece mold of the wheel.
perhaps it is your poor description that doesn't help matters.

are you talking about casting the whole wheel rim or just wanting the spoke pattern to use seperately?

[willimo]

I've cast just the wheel face too, though I had cut the face off the hoop to do so, so I find this very helpful.

I guess you all are a lot better at casting resin than I am. If I try to cast a whole wheel in a two-piece mold, I get bubbles everywhere in the hoop and it's awful, and I have a very hard controlling quality in the wheel face. This is why I cast just the wheel face, and had good success.

Some of us have to come up with good tricks to make up for our skill or equipment deficiencies, and I think this is a great tip for us. If you look at the face of the suggestion, it's pretty good. Thanks!

[willimo]

Also, when I did just the face, I have so many donor wheels I could just match the rarer face with the leftover hoops.