Why should I sand the glass?

Hey gals/guys!
I just finished glassing a hollow wood single fin shortboard. It is my first board, so I’m not entirely sure how to proceed.
It looks kind of neat right now and me and my help-buddy were wondering, if it is necessary to sand it down.
I am just going to leave it at one layer of glass and the surface roughness seems nice to wax, but then again, I’m unsure if it’s really necessary to sand it. Also, I planned to leave the finished board without gloss.
If you could give me your opinions, I would be very thankful :slight_smile:

Yes you need to do a hot coat and sand the hot coat smooth.  Otherwise the laminating resin will stay sticky, and all the little bumps will rip your skin off.

If its a HWS then there is a good likelihood its epoxy resin, so the tackiness won’t be an issue. But I still agree with everysurfer it needs a second coat to fill in the weave.

These guys don’t have a clue as to what they are talking about! :slight_smile:

Go full nipple ripper! 

“Seal the deal” -Stingray

http://www.swaylocks.com/forums/first-epoxy-glass-job-s

It’s worth reading the whole thread

Okay, thanks for the answers. I used epoxy resin, btw :wink:
If you allow, I’ll summarise hot coating, to see if I understood it correctly:

  1. Sand the laminated board with 120 grit paper
  2. Mix a new resin batch
  3. Spread it on one side, putting tape around the rails at half thickness
  4. Let it cure
  5. Repeat for other side

+1

I don’t sand before hotcoating (with epoxy it’s actually known as “fill coating”) and I am pretty sure most other folks don’t either.

How long ago did you laminate?

You wanna do all your steps within a few hours of the previous.

I laminated on Wednesday evening. Is that too long ago, or doesn’t it matter?

Do not sand epoxy lamination coat. To late this time, but on the next board, when the epoxy is not sticky, but still a little rubbery, trim anything that needs removing with a block plane, or razor blade. After its not rubbery, use an auto body file.

Don’t sand the cloth.

Yes, on future boards get the fill coat on soon after the lam as everysurfer says. Beyond this what is called amine blush comes through and the next coat won’t bond very well. The blush can be removed by sanding, but then you’re sanding the cloth (not what you want), to avoid sanding scrub the board with water and a scouring pad (like you do the dishes with). The blush is water soluble so do this thouroughly and then do the filler coat. 

Depending on the expoxy you’re using it is a good idea to do a UV inhibiting clear coat or varnish to finish with.

Cheers

JB