Re: How to repo a body...
Posted: Tue Mar 04, 2008 10:42 am
well done mate ![Smile :)](./images/smilies/icon_smile.gif)
![Smile :)](./images/smilies/icon_smile.gif)
That looks great Robert. Nasty drying time though. It might be worth the cost of drying to go with Lexan. The .030 stuff requires 1 hour at 90 degrees.ROH73 wrote:The plastic sheet needs to see about 150 F for several days prior to vacuum forming.
Robert
Thanks, MOmo.MOmo wrote:The body looks amazing considering.
I had a buddy who works/worked for Nike (corporate HQ is around the corner from my work) and he was a shoe designer. He had access to a mold machine and vacu-forming. He made a couple of models but i can't recall what material he used for the mold. I know the "lexan" wasn't very thick, but his rationale was he could make multiple bodies and essentially used them as "basher" shells. I think he used a TC shell for them. Might have to call him and see if he still does it, haven't talked to him in a # of years.
On another note. any ideas how you might go about repo bodies that are cut out and perhaps even painted? I race w/ a guy who has an old stadium "jeep" body but its mounted and painted. I was trying to think of a way to fill in the areas where the lexan was removed IE wheel wells, and the fr and r.
MOmo
That is a great idea. When my dad was big into wood working, we built our own kiln and used a few 100 watt bulbs to keep the temps up. It worked great and was gentle on the power bill. The dimmer is a trick idea also. I like it. Think I might have to copy your idea on that one.ROH73 wrote: In any case, I think I can get the time and temperature I want pretty cheaply by building a drying box with incandescent bulbs as the heat source. A couple of 75 watt bulbs can get pretty hot in a relatively small enclosed space. Add a dimmer switch to "control" the temp and I think that should do it.
MOmo wrote:The body looks amazing considering.
I had a buddy who works/worked for Nike (corporate HQ is around the corner from my work) and he was a shoe designer. He had access to a mold machine and vacu-forming. He made a couple of models but i can't recall what material he used for the mold. I know the "lexan" wasn't very thick, but his rationale was he could make multiple bodies and essentially used them as "basher" shells. I think he used a TC shell for them. Might have to call him and see if he still does it, haven't talked to him in a # of years.
On another note. any ideas how you might go about repo bodies that are cut out and perhaps even painted? I race w/ a guy who has an old stadium "jeep" body but its mounted and painted. I was trying to think of a way to fill in the areas where the lexan was removed IE wheel wells, and the fr and r.
MOmo
If everything is supported very well, it may work. I don't know about casting resin, but wet gypsum is quite heavy.bngiles wrote:
I've pondered that as well. If the body was cut out right where the original cut lines were, couldn't you use a wide tape to fill in the sides? We have this ultra heavy 4" wide masking tape at work. If you just made sure it stuck well enough to be leak proof around the edges, it might work. Of course you would have to support everything when pouring in the material, but you would have to do that anyway. Just tape over any holes in the body too. Can Ultracal and the like be sanded after setting? Any difference in texture of the tape would be cut out anyway.
Go for it! Maybe you can work the bugs out and let me knowTadracket wrote: That is a great idea. When my dad was big into wood working, we built our own kiln and used a few 100 watt bulbs to keep the temps up. It worked great and was gentle on the power bill. The dimmer is a trick idea also. I like it. Think I might have to copy your idea on that one.
Sure, that could be done. The only problem lies in the detail that's lost from the thickness of the polycarbonate. When you take a mold from the inside of a body, you're for the most part replicating the original mold it was formed over. When you take a negative from the outside and then make a positive, the repro body will look less like the original. It will be about 0.020" bigger and will have less detail.MOmo wrote:I was even thinking of doing a "reverse" mold, though it would be more time consuming, trying to strip the stickers or other material from the ourside of the body.
Then laying it in a box with a material ie plaster, bondo etc. and then setting the body in it. Again, the difficulty would be if the body was cut out, trying to replace the lost material and recreate a body that way. Then letting the body dry, it would create a mold for making a solid mold. So, essentially the reverse of what others are doing, though i guess its the same. starting with a piece of plastic and making a mold of it. Making the mold from the outside not the inside.
MOmo
I guess it comes down to the purpose. IF you cared about the detail then yes it woul be lost, but if the overal design was what someone wanted, would it matter? I guess the purist in me would want detail. The realist in me wants the design and the accurate shape. But I see both sides. I thought about that too, the detail, and figured that it would be a given that it could be lost doing it from the outside.ROH73 wrote:Sure, that could be done. The only problem lies in the detail that's lost from the thickness of the polycarbonate. When you take a mold from the inside of a body, you're for the most part replicating the original mold it was formed over. When you take a negative from the outside and then make a positive, the repro body will look less like the original. It will be about 0.020" bigger and will have less detail.MOmo wrote:I was even thinking of doing a "reverse" mold, though it would be more time consuming, trying to strip the stickers or other material from the ourside of the body.
MOmo
Still, that might be better than nothing for a painted body, etc.
Robert
I think You're right; many people would be happy with just the overall shape.MOmo wrote: I guess it comes down to the purpose. IF you cared about the detail then yes it woul be lost, but if the overal design was what someone wanted, would it matter? I guess the purist in me would want detail. The realist in me wants the design and the accurate shape. But I see both sides. I thought about that too, the detail, and figured that it would be a given that it could be lost doing it from the outside.
MOmo