---
catalog: WEB-I3
catalog_name: Insulating Glass Fabrication Supplies
page: 19
sku_count: 0
generated_at: "2026-05-21T23:30:08Z"
---

# Insulating Glass Fabrication Supplies -- Page 19

## Page Content

FHC INSULATING GLASS FABRICATION, SUPPLIES, AND EQUIPMENT
SECTION 2
FHC IG Fabrication Methods
IG17
Bulk Quantities Available
Click to Chat With Us
IG Kits
Visit fhc-usa.com to search for
Enter the Item Number or scan QR code with  
your smartphone for complete product details
Dual Seal Unit Fabrication
Polyisobutylene Primary Seal, Two-Part Polysulfide, 
and Urethane Secondary Seal Method
When fabricating a dual seal unit with 
FHC products, follow these steps:
PIB Tape Application:
Apply PIB Tape to one side of the 
assembled spacer frame.
Set the spacer on the first clean glass 
lite, maintaining a 3/16-inch gap 
between the spacer and the glass edge.
Apply PIB Tape to the facing side of the 
spacer, ensuring an even sight line.
Place the second clean glass lite on the 
spacer with square and even corners, 
using weights to compress the PIB Tape 
for a good seal.
Sealant Mixing: 
Thoroughly mix the base compound and 
accelerator as per FHC’s specified ratio 
using a spatula or low-speed mechanical 
mixer. Mix only the required amount 
for the units to be assembled. The 
mixed material typically has a one-hour 
application life at 70°F (21°C).
Unit Clamping:
Ensure a tight seal by clamping the 
glass units on all sides using spring 
clamps with vinyl-coated jaws. When 
sealing multiple units, stack them with 
separation using wood blocks or paper. 
Place wood blocks about 1 inch from the 
edge and 4 inches from the ends. Begin 
with the largest unit at the bottom. If 
the units are the same size, use paper 
between them, but do not stack more 
than 15 larger units.
Bulk Gun Application:
Load the sealant into a bulk gun and 
apply it to the unit edges.
Ensure adequate sealant to penetrate 
the spacer shoulders for a proper seal.
Avoid excessive sealant that may 
displace the spacer. Focus on applying 
extra sealant to the vulnerable corner 
areas. After curing, remove excess 
sealant with a razor blade, taking care 
not to damage the edge seal.
Glass Panels
Desiccant
Spacer
Secondary 
Sealant
PB
Check for Newton Ring:
Inspect the bottom units of the stack for a “Newton 
Ring” effect in the center of the unit. This occurs when 
two pieces of glass are in contact.
If you observe a Newton Ring, flip the affected units 
upright and repair them before transport to prevent 
permanent rub marks.
Following these steps will help ensure a proper seal 
and the longevity of your insulating glass units using 
FHC sealant.
FRAMELESS HARDWARE COMPANY LLC
2323 Firestone Blvd. South Gate, CA 90280 
Toll Free: (888) 295-4531  |  Direct: (323) 968-2031
Fax: (323) 336-8307  | fhc-usa.com