Plaster Mandrels alternative materials for washout mandrels (fiber glass air ducts) 1

[Cisnerjo]

Hello,

Composite experts community, I would like to request your expertise in order to look for an alternate material to make mandrels used for aircraft ducting. Right now, we are producing this mandrel using a plaster type material which it works for the type of duct we are currently producing but we would like to expand our process to build more complex shapes (longer (up tp 8' long) and smaller diameter (0.75" overall diameter) tubing. So the material we are actually using won't comply with it since it's hard to be removed. We used water and perform some type of banging and wiggling to get it out once the prepreg is cured. For the long and small diameter tubes we pretend to make this practice is not going to work so we will need a water-soluble material that could be dissolved at contact with water. I heard about the salt madrels but also heard it's not so environmentally friendly. So, we are looking for a different option.

Does any of you all have work or has any experience with water soluble materials that could be used for prepreg ducting manufacturing? I appreciate your support on this.

Best Regards

 

[SWComposites]

couple of links from Google search for "water soluble mandrels"

https://acmtucson.com/products/

https://northerncomposites.com/wash-out-tooling-materials/

https://soltecaz.com/products/

probably other options

 

[Cisnerjo]

Thanks a lot for your response and support ! SWComposites