you guys have probebly heard this a million times but im new to composited and when making my first mould the pva just beaded off like water on plastic. i applied it with a sponge brush. this was done after 4 coats of wax on the board and plug. alternatvly i just washed it off and went with wax only and it was fine but is there a way to stop the beading if i need to use it in the future?
thanks in advance
Use special wax for PVA. Most release waxes will cause your problem.
the wax i use is carnauba based from easycomposites and ive seen pva used over it loads of times.
thanks
Take a prime wax for PVA and do not believe everything you see;)
PVA is the problem 
Release waxes are oily/greasy, thats why they work. Most liquids will form drops. Or you could use a degreaser, whipe it of, and then apply PVA (have seen that happening before…)
Using release wax with PVA is useless, and will result in a bad surface quality. Use wax(or even better, semi perms) and stay away from PVA as much as possible. Only use PVA where you have too(bad surfaces, both in quality as in materials)
You could use a priming wax, or just standalone PVA.
think ill stick with just wax for the time being.
I’d suggest you look into a different release coating system than wax and pva. Get something like Zyvax sells. Enviroshield or whatever. You parts will jump right out of the mold and have a better surface finish than wax and pva.
Wax is fine for pulling off a plug but when it comes to pulling parts from mold go to a semi perm like freekote.
It really depends on the wax. You can shoot Part-all Film #10 (PVA) directly on Part-all Paste #2 (release wax) without any beading. If beading is an issue then the need to do several mist coats of PVA onto the wax and let them completely set up. Then you can move to a flowing coat. If you are wiping on the PVA then you can applying it with a small cotton clothe. You want to wipe it on in circular motion until the PVA starts to set-up. The beading will then cease. Your next coat can be brushed on for a better finish.
Sometimes PVA is mandatory to the process due to the reactivity of the components involved. Wax cannot block reactivity. I can guarantee that some release surfaces will react with some resins no matter how many coats of wax you apply. If you don’t know how the different components react with one another then the absence of PVA in the system can result is catastrophic sticking.
Also, if the surface finish on your plug is rather “bland” you can make it better with PVA.
Here is a great article explaining why PVA is sometimes necessary. - Why Mold Stick
And here is what I have on spraying PVA. Make sure you add some colour to the PVA or you will have no clue of what you are doing.
If you have to use PVA purchase one of those $10 aerosol sprayers with the glass jars. Pour your PVA in there then spray away :).