sanding between layers?

Hi, I am currently practising the lay up process on a square piece of wood. Before I start mt project of giberglassing a wooden banana boat.
So far I have applied 4 coats of mat resin sanded it down smooth and cleaned the surface with acitone. Today I applied a coat of gel coat, this was my first time and while I tried my best to make it as smooth as possible it still looks abit rough. What do I do once this layer has hardened? Do I sand it smooth again before applying the next coat of gel?

 

John; What you have done is not entirely clear. You have mentioned matt. If you are covering a wooden boat with FRP you do not normally use matt. Matt would be used only in the case where you needed to add a signifigant amount of strength to the skin of the boat. Roughness is almost a certainty when you use that kind of glass.

If you wish to cover the boat for some added protection and durability, you will use cloth, not matt. The weave of the cloth can be filled with resin without great difficulty, thus delivering a fairly smooth finish. Matt is just a collection of glass strands that are randomly placed. Filling that kind of material on an outer surface is smitten with difficulty and smoothness is rarely the result. Matt will also add much more weight than cloth covering.

Please explain more of the details about what you are doing.

 

You mean thickness.

And this is a duplicate of the thread!

There is a similar one by the same thread opener where already several comments have been made.

Regards
Richard

 

Yes thickness would have been a better word.