[flaco]

So I've got a new project I'm working on and I'm trying to save some time and sanity by keeping my grinding to a minimum. The existing deck has got some flex in it, and I was looking to lay a few layers of cloth over it to stiffen it up. My question is, do I need to COMPLETELY remove the existing gel coat/paint (not sure which one) before I lay up the new glass?

I was also considering covering the existing deck with 1/4" plywood encapsulated in epoxy (for both stiffness and looks). If I just use epoxy adhesive over the existing gel/paint to bond the plywood to it, will it stick, or do I still need to grind the deck first?

Thanks in advance.

 

[Brett]

I wouldn't attempt to 'glass or bond to existing gelcoat or paint.
I sand off the existing finish back to bare 'glass/resin,
then start with repairs or modifications.
I've seen the results when 'glass is laminated over existing finishes.
Separation, cracking, peeling...not good.

 

[flaco]

OK, thanks a lot for answering that for me. Just one more question though.
What tools do you use for this?
I have tried in the past:

4" grinder - tears through way too fast

6" disk sander - better, but still I end up with a lot of pits and low spots/uneven finish

Palm sander - Waaaay too slow

Do I just have no skillz?

I wouldn't attempt to 'glass or bond to existing gelcoat or paint.
I sand off the existing finish back to bare 'glass/resin,
then start with repairs or modifications.
I've seen the results when 'glass is laminated over existing finishes.
Separation, cracking, peeling...not good.

 

[Brett]

I used a cheap pneumatic with wet/dry paper and running water.
Water kept the paper clean, moved the dust from under the sander
without putting dust in the air so no respirator or tyvek suit needed.

 

[johnfaris3]

This was from a past issue of West System Epoxyworks:

http://www.jamestowndistributors.com/userportal/document.do?docId=370&title=Preparing+laminates+-+West+System

 

[sjd0004]

I used a cheap pneumatic with wet/dry paper and running water.
Water kept the paper clean, moved the dust from under the sander
without putting dust in the air so no respirator or tyvek suit needed.

I thought wet sanding was only for fine grit papers. How does that work with something like 120?

 

[Brett]

Wet/Dry is available all the way down to 60 grit.
Running water keeps the old paint and gelcoat dust
from clogging the paper, so the paper cuts better and longer.


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