front Grille Continued. PVA.

This next step continues with the Mold Release process by using a chemical agent called Polyvinyl Alcohol (PVA). PVA is typically sprayed on top of a mold as a mold release agent. The chemical forms a very thin film over the surface of the material which allows the produced composite piece to pop out of the mold.

As you can see by the warning labels, this chemical can be very hazardous to your health. Prolonged exposure to these types of chemicals can lead to Lung Cancer. The bottom line is, enthusiasm is supposed to be fun and entertaining your interest, there really isn’t any room to sacrifice your longevity and health.

Make sure you are properly protected and spend the money doing so. You can purchase a standard oxygen breathing system from 3M at your local hardware store. Make sure you purchase a professional series of filtering masks that allows you to protect from the proper chemicals and compounds. Mine came with two standardized oxygen/dust filters.



The Pink Cartridges to the left are the ones provided for Dust filtration. These won’t protect you from Volatile chemicals such as PVA. What you need to purchase is a PVA specific filter. 3m offers a variety of different cartridges/filters for different applications. You can see here that the mask allows you to snap on different cartridges for different jobs. Make sure you read the labels on your cartridges carefully. They have a specific life span and after a certain length of time, they won’t be able to protect you anymore. At the same time, they should be sealed when not in use so that no contaminants get into the cartridge filter.

The reason why I’ve decided to use both Mold Release Wax as well as PVA is due to the fact that most professionals swear by this process. Some have tried to use only the wax solution, but it resulted in the damaged molds where wax wasn’t present. You can only rub the wax into so many points on the mold piece whereas the PVA is a liquid and can seal the areas where the wax has not protected.

I was very very generous with my PVA coating. It is typically applied with a spray gun which allows for even distribution. Being that I don’t have a spray gun like that, I utilized my mighty 1 dollar disposable brush. If you are a crafty enthusiast like myself, yes, I’m damn crafty, make sure you discover the correct sources

for your tools. These brushes are cheaper than the ones at a Dollar store and are meant to be disposed. Their sales pitch is:

It is good enough to use, but cheap enough to throw out.

I applied the first coat of PVA and allowed it to dry in a well ventilated area *this is a must* for approximately an hour.

Remember that I have 5 coats of mold release wax on the Grille already? Well you can see how uneven the PVA dried because of the Wax. I think this is due to two reasons.

1. I didn’t buff the wax down into the Grille as best as I could.

2. The PVA was a brush on application. Not the best way of doing things.

To fix this I decided to apply a second coat of PVA, propping up the piece to reduce the angle for the application so that less run off would be apparent. The result of the 2nd coat of PVA is as follows:

You can see the results are much better.

Finally. Here is a quick photo of what the PVA film looks like when it flakes off. I accidentally dropped the piece before putting on the 2nd PVA coating, and this is what the PVA film looked like when it was off the mold.

Stay tuned for further developments on this project!

front Grille Part 1:  Click Here

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About awdaltima

Architect
This entry was posted in Aerodynamics, Aesthetics. Bookmark the permalink.

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