mold
11-19-2005, 07:31 AM
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mold
Hi everyone
what is the best way to pull a part from this mold ? Do I need to vacuum bag it or will the carbon fiber go into the mold better when it is wetted down with the epoxy. The mold is all ready waxed down ready to go
Thanks
troy
what is the best way to pull a part from this mold ? Do I need to vacuum bag it or will the carbon fiber go into the mold better when it is wetted down with the epoxy. The mold is all ready waxed down ready to go
Thanks
troy
11-20-2005, 09:22 AM
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RE: mold
Well, nobody else seems to want to answer so I might as well. A bit more information would have been useful.
This looks like a wing tip mold. To start I would would lay in a layer of two ounce cloth DRY. Poke the cloth down into the mold and all around the deep sharp bottom. I would then apply resin to saturate the cloth. To give the part some body the next layer would be 4-6 ounce cloth. This will soak up any excess resin. The only difficult part I see is ensuring there are no cavities around the sharp edge in the bottom of the mold. Some filler may have to be used there. I do not know what the carbon is for. The cloth weights can be varied to suit the strength/weight requirement.
Ed S
This looks like a wing tip mold. To start I would would lay in a layer of two ounce cloth DRY. Poke the cloth down into the mold and all around the deep sharp bottom. I would then apply resin to saturate the cloth. To give the part some body the next layer would be 4-6 ounce cloth. This will soak up any excess resin. The only difficult part I see is ensuring there are no cavities around the sharp edge in the bottom of the mold. Some filler may have to be used there. I do not know what the carbon is for. The cloth weights can be varied to suit the strength/weight requirement.
Ed S
11-20-2005, 11:04 PM
#3
RE: mold
Troy,
A little more info on your mold would help. I think Ed is right in that it is a wing tip mold but without some indication of size, it would be hard to suggest exactly how you would want to lay it up. How big it is, what is the intended use, do hard points need to be molded in for rigging lights or attachment screws, plus a few other variables come to mind?? I'd be glad to suggest how to do it, and a bit more information would sure help. You don't want to make it too flimsy or without any proper supports and/or carbon fiber imputs to add strength. Let us know and I'll bet you get a few more replies plus I would be happy to help.
Dan
Carolina Custom Aircraft
A little more info on your mold would help. I think Ed is right in that it is a wing tip mold but without some indication of size, it would be hard to suggest exactly how you would want to lay it up. How big it is, what is the intended use, do hard points need to be molded in for rigging lights or attachment screws, plus a few other variables come to mind?? I'd be glad to suggest how to do it, and a bit more information would sure help. You don't want to make it too flimsy or without any proper supports and/or carbon fiber imputs to add strength. Let us know and I'll bet you get a few more replies plus I would be happy to help.
Dan
Carolina Custom Aircraft
11-20-2005, 11:25 PM
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RE: mold
Hi Dan /Ed
The mold is about 20cm long and only 10 wide. The parts are used for the cheeks on a pattern aircraft they will be attached to the side of the balsawood sides then covered in fiber glass. They have a small narrow curve at the top and end up being about 5 cm towards the larger end . I need suggestion on what wieght cloth to use in the mold to start with then I have carbon fiber cloth to reinforce after the fiberglass cloth. The parts will be epoxied to the airframe. The the whole frame will be fiberglassed filled and painted
Is that all the information required please let me know anything else please
Thanks
Troy
The mold is about 20cm long and only 10 wide. The parts are used for the cheeks on a pattern aircraft they will be attached to the side of the balsawood sides then covered in fiber glass. They have a small narrow curve at the top and end up being about 5 cm towards the larger end . I need suggestion on what wieght cloth to use in the mold to start with then I have carbon fiber cloth to reinforce after the fiberglass cloth. The parts will be epoxied to the airframe. The the whole frame will be fiberglassed filled and painted
Is that all the information required please let me know anything else please
Thanks
Troy
11-21-2005, 07:30 AM
#5
RE: mold
Troy,
That info helped. My suggestion is a bit different from Ed's, but.. here goes. First, considering this is to be a non load bearing surface, I suggest a two layer layup, the first of 2 oz as Ed suggested and the second of 6 oz. To do this, first lay down a nice even coat of epoxy (at least 2 hour set time, I use 12 hour) in the mold first. Don't worry about too much, the second layer will soak it up. Second, mix up a mixture of Cabosil and epoxy to the consistancy of very thick honey and using a baggy, snip the end a put a line of this into the very thin edges of the mold. Even 2 oz cloth will not get into those very small areas, but the Cabosil/epoxy will. Let the cabosil mixture set up for about 15 minutes, and then put in the layer of 2 oz , dabbing the fabric in place with an up and down motion, making certain all areas you can get to have the cloth nice and even. If you need to cut the cloth, making a dart, to make the cloth lay evenly, do so. Immediately after the 2 oz, apply the 6 oz. Make certain all of the fabric is saturated. If it isn't, try to move some epoxy from one area to another, or just dab some more in. Then just wait till it sets up, and twist and pop from the mold. Hope this helps..If you have any more questions, just ask.
good luck,
Dan
Carolina Custom Aircraft
That info helped. My suggestion is a bit different from Ed's, but.. here goes. First, considering this is to be a non load bearing surface, I suggest a two layer layup, the first of 2 oz as Ed suggested and the second of 6 oz. To do this, first lay down a nice even coat of epoxy (at least 2 hour set time, I use 12 hour) in the mold first. Don't worry about too much, the second layer will soak it up. Second, mix up a mixture of Cabosil and epoxy to the consistancy of very thick honey and using a baggy, snip the end a put a line of this into the very thin edges of the mold. Even 2 oz cloth will not get into those very small areas, but the Cabosil/epoxy will. Let the cabosil mixture set up for about 15 minutes, and then put in the layer of 2 oz , dabbing the fabric in place with an up and down motion, making certain all areas you can get to have the cloth nice and even. If you need to cut the cloth, making a dart, to make the cloth lay evenly, do so. Immediately after the 2 oz, apply the 6 oz. Make certain all of the fabric is saturated. If it isn't, try to move some epoxy from one area to another, or just dab some more in. Then just wait till it sets up, and twist and pop from the mold. Hope this helps..If you have any more questions, just ask.
good luck,
Dan
Carolina Custom Aircraft
11-23-2005, 09:00 AM
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RE: mold
Hello.
One other thing.
If the mold has a good surface finish (impossible to see from the picture) then the molded part will also have a nice surface finish.
In that case, I would not have wanted to cover it up with fiberglass after glueing it in place. I would glass the fuselage, glue on the molded cheeks, and finish with filler.
Magne
One other thing.
If the mold has a good surface finish (impossible to see from the picture) then the molded part will also have a nice surface finish.
In that case, I would not have wanted to cover it up with fiberglass after glueing it in place. I would glass the fuselage, glue on the molded cheeks, and finish with filler.
Magne
11-23-2005, 12:03 PM
#7
RE: mold
Not only is carbon fiber overkill for this application, it would be very difficult to get it to conform to the tight radius at the bottom of the mold. I would consider going with a layer of 3/4 oz under a layer of 3 - 4 oz. You will get all the stiffness you need from the shape, and a good glue joint to the fuselage.
