Question about fiberglass

[Fett80]

I have been working on a paintball mask witch I am very proud. You can see pictures of it here.

http://www.therpf.com/f24/my-paintball-helmet-123020/

I have casted the helmet with Smooth On cast 300. But it turn out that I have a hard time controling the tickness of the plastic and the helmet have weak points.

Witch bring me to try to find alternative casting product. I want to make my next cast in fiberglass. But I dont know if the fiberglass resin will get all the detail in the mold. Anybody tried this before?

Should I make a first layer of resin only before adding fiberglass? Is the resin fragile when not reinforce by fiberglass? How thick can I make my first layer of resin before it become fragile. I have bought some fiberglass powder and some resin thickener to put into the tight places in the mold.

The helmet will be used in paintball games. So it has to be resistant to some minor impact.

I have never worked with fiberglass before so any advice would me very much apreciated.

 

[terryr]

Can you put the cloth onto the 300?

 

[BGHUNTER]

If you have a negitive mold of the mask, before laying the glass cloth you should either brush or spray some gelcoat (witch is basicly thicker fiberglass resin) in to the mold you could even use just the laminating resin it will work the same just gelcoat is thicker and beter to work with once dry,
any way so do a few layers or the resin/gel coat ,I usually do 3 layers of gel coat, then ill place on the fiberglass cloth , a strip at a time (I use the matting cloth not the tape stuff as it doesnt work as well, and pre cut it to strips depending on the shape Ill work out the best size to cut the pieces) , then ill place it were I want it and then brush on some laminating resin continue this till the entier mold is covered with the FG and let it dry to a tacky stage and repete 1 0r 2 times then let it dry a bit furether then ill sand down the sharp bits then ill do one more layer , , because its been sanded this layer should be pretty smooth, let dry sand again then brush on 2 or 3 layers of gel coat or laminte resin between each coat sand don and youl get a nice smooth finish that wont scrtcch you ,
And then and only then take it out of th mold\\If you folow this youl have a nice strong mask that will take hits from a paint ball gun no problem , the key to the strength is good strong layers of overlaping weave and sturdy thick resin,

 

[Fett80]

If you have a negitive mold of the mask, before laying the glass cloth you should either brush or spray some gelcoat (witch is basicly thicker fiberglass resin) in to the mold you could even use just the laminating resin it will work the same just gelcoat is thicker and beter to work with once dry,
any way so do a few layers or the resin/gel coat ,I usually do 3 layers of gel coat, then ill place on the fiberglass cloth , a strip at a time (I use the matting cloth not the tape stuff as it doesnt work as well, and pre cut it to strips depending on the shape Ill work out the best size to cut the pieces) , then ill place it were I want it and then brush on some laminating resin continue this till the entier mold is covered with the FG and let it dry to a tacky stage and repete 1 0r 2 times then let it dry a bit furether then ill sand down the sharp bits then ill do one more layer , , because its been sanded this layer should be pretty smooth, let dry sand again then brush on 2 or 3 layers of gel coat or laminte resin between each coat sand don and youl get a nice smooth finish that wont scrtcch you ,
And then and only then take it out of th mold\\If you folow this youl have a nice strong mask that will take hits from a paint ball gun no problem , the key to the strength is good strong layers of overlaping weave and sturdy thick resin,

Thanks for the precious information!!

 

[BGHUNTER]

I hope its of some use,