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Old 08-18-2018, 07:12 PM
sblack sblack is offline
Join Date: Dec 2009
Location: Montreal
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Default Source for sheet plastic

I have seen a bunch of videos of people laying up glass between sheets of plastic, usually 3 or four mils thick. I checked my local big box stores and they didn't have anything, or I wasn't looking in the right place. Can anyone suggest a good source? I would like to try this method.
Scott Black
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Old 08-18-2018, 07:24 PM
David Paule David Paule is offline
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Local hardware store, paint store, etc.

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Old 08-18-2018, 07:41 PM
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walter walter is offline
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I use extra large ziplock bags found at my local grocery store. Trim off the sides and top with a rotary cutter.
Walter Tondu
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Old 08-18-2018, 08:08 PM
rv7charlie rv7charlie is online now
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Look for painter's plastic drop cloth.
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Old 08-18-2018, 09:10 PM
Charles in SC Charles in SC is offline
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Are you wanting to create a sheet of fiberglass? I have made several during my build. I taped a sheet of wax paper to a sheet of aluminum, then laid up the fiberglass on the wax paper, then put saran wrap on top of this and smoothed it out as needed. This makes a smooth piece on only one side. Maybe you could press something flat on top while it sets up so as to flatten out the top surface. Hope this helps. Most big box stores sell plastic sheet for vapor barriers, drop cloths etc.
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Old 08-18-2018, 09:27 PM
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az_gila az_gila is offline
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4 mill and 6 mill clear plastic sheeting are stock items at my local Home Depot

The thicker stuff is much easier to work with.
Gil Alexander
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Old 08-19-2018, 04:44 AM
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snopercod snopercod is offline
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Location: Asheville, NC
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Default Use trash bags

What you want to use are the white non-scented kitchen trash bags. Black trash bags work OK, too, but you can't see through them as well. Lay down the first piece of plastic on a smooth workbench. Place however many layers of fiberglass you want (four is my limit), cut oversize, on the plastic in the proper orientation. Pour on the epoxy and spread it around with your 6" Thalco rubber squeegee. Wait a few minutes while the epoxy penetrates all layers (use a hair dryer to speed up that process). Squeegee off the excess epoxy being careful not to disrupt or pull the weave of the cloth. I use a tongue depressor to scrape the excess epoxy off the squeegee and back into the mixing cup.

When you've removed all the excess epoxy from the cloth, apply the second sheet of plastic on the top. Use a "pizza cutter" (available from ACS) to cut the sandwich to the desired size and shape. Remove the bottom layer of plastic and apply the fiberglass to the prepared workpiece. Use paper towels to remove any air bubbles and smooth out the cloth. Peel off the top piece of plastic and use a 1" chip brush (cut on an angle) to stipple out any remaining air bubbles. Apply peel ply in areas where you will be bonding something else to the top surface or where you want a feathered edge. (Keep in mind that using peel ply adds weight.) Clean up your tools and gloves with Acetone.

Safety note: Wear Butyl rubber gloves with cotton liners during this process.
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Last edited by snopercod : 08-19-2018 at 04:47 AM.
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Old 08-19-2018, 05:50 AM
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DanH DanH is offline
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Vapor barrier. Standard construction material.

See posts 67 and 68, this thread:
Dan Horton
Barrett IO-390
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Old 08-19-2018, 08:04 AM
sblack sblack is offline
Join Date: Dec 2009
Location: Montreal
Posts: 1,322

Vapor barrier - that's it! Thank you. By the way, I tested my epoxy pumps. 20% low on hardener! I will just use them as convenient dispensers from now on. Thanks for that tip too.

Thanks to all who responded.
Scott Black
RV 4, O-320, wood prop, MGL iEfis Lite
VAF dues 2019
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