Fiberglassing over plywood ...

[GPW]

Thought this might be helpful.. :thinking
:https://www.youtube.com/watch?v=-2sh9hrIyHQ

[tony.latham]

Thought this might be helpful.. :thinking
:https://www.youtube.com/watch?v=-2sh9hrIyHQ

I was pretty surprised to see him using polyester resin over wood. If you've got barrels of it in the shop, it is what it is.

Take a look at this comparison. Epoxy v. polyester over wood:

https://youtu.be/WxsnPheiTWo?si=ZAeU90Nv4P_-B5kQ

I quit polyester twenty years ago.

Tony

[Pmullen503]

Having used poly for years boat repair or construction, I couldn't believe he could work with it without a charcoal respirator.

[saywhatthat]

ploy over wood . do more research! if you are where it freezes will lift the glass if water gets under. make sure you pant it . ploy has pores If you are going to glass it why waste time and cash and weaght . with ply wood . There is cheap foam that ploy does not eat

IMG_20211102_180503 (1).jpg (38.78 KiB) Viewed 303 times

[MickinOz]

I am in possession of a book on fibreglassing wooden boats. It was written by a man who made a living out of rescuing east coast lobster boats, in the days before the availability of epoxy resins.
There are some tricks to getting polyester based fibreglass to adhere to plywood. I'll dig it out.

[GPW]

Although we personally gave up on polyester resin decades ago in favor of Epoxy , I did like his application methods ... I hadn't realized the mat fabric would adhere better to plywood ...

[Pmullen503]

One thing to remember is he's laying up way more glass and resin than we would ever need over trailer walls. You use matt when you want to rapidly build thickness (and weight).

Remember, think airplane not tank (or boat).

[tony.latham]

realized the mat fabric would adhere better to plywood ...

Mat drives me crazy. It's messy.



Removing a layer of 4 or 6 oz. cloth from plywood using epoxy is damn near impossible. Sure, if you don't trim it and leave a few inches of saturated cloth for something to grab, it can be done, but not a properly laid up and trimmed piece, and it's going to be tough.

Tony