Fibreglassing questions

[chamy]

Hi guys,

I did some fibreglassing last night which went fine.

It will be fulled cured by now, so when I have another chance this evening, I planned to add more layers.

Do I need to scuff yesterdays fibreglassing or is it ok to just go straight over it?

I also have some filler additive from an epoxy kit (west system 407). It basically just looks like a tub of dust, that youre supposed to mix in the epoxy. Would this be okay to add to the fibreglass resin im using (polyester) to use as a filler?

 

[langy]

Cured glass has a semi shiny surface so yes you need to rekey.
The white dust if I remember right is called blown glass fibre, you can use as filler but it has little strength.

 

[Ed.]

If you used unwaxed resin then no need, however if there are corners and bends then I would just quickly run some coarse sandpaper over the edges to remove any spikes that may have formed, you don't need to add any filler to the resin unless you are making a bogging paste or to use as a fairing paste, (to remove low spots prior to final sanding before painting).

If you are using it as a fairing paste then add some wax in styrene solution (5%) to the mix as that will help to stop the sandpaper clogging up when you sand. But you will have to sand the entire surface before you paint it as the wax will not give the paint a good bond to it.

If you are not sure if your resin is waxed or unwaxed, after curing the unwaxed resin will feel slightly sticky whereas the waxed will be slippery.

Cheers

Ed.

 

[julieanncharters]

Hi guys,

I did some fibreglassing last night which went fine.

It will be fulled cured by now, so when I have another chance this evening, I planned to add more layers.

Do I need to scuff yesterdays fibreglassing or is it ok to just go straight over it?

I also have some filler additive from an epoxy kit (west system 407). It basically just looks like a tub of dust, that youre supposed to mix in the epoxy. Would this be okay to add to the fibreglass resin im using (polyester) to use as a filler?

yes always do a quick sand with 40grit sandpaper to remove any fingers before next coat of mat.
if you don't you'll get raised points and trapped air.
if you want a cheap filler just add talcum powder to normal resin.
if you need a lot by a bag of the stuff from resin suppliers.
have fun