Core-Bond B70 is a polyester-based core bedding compound, developed for both hand-layup and vacuum-bag core installation, and
is used as a 2-part system in conjunction with a priming resin applied to the core surface. Lightweight and non-sagging, Core-Bond is
formulated to the degree of elasticity required for the core to skin interface. With a shrinkage of less than 1%, Core Bond significantly
reduces the possibility of print-through. Core-Bond is easily applied with a (6mm) V-notch trowel, and achieves a thin bond line of
approx. 1/32 -3/64 (approx 1mm). One gallon (3.78l) covers approx. 30 square feet (3m
2
). Always prime core surface with a catalyzed
resin. The Core-Bond combines with the priming resin for a thorough cure and good cohesion. The priming resin should appear between
the blocks of contoured foam, or in the bleeder holes of plain foam, for a visual inspection of a good bond. Core-Bond is catalyzed with
a green BPO paste catalyst supplied by ATC. Other Core-Bond types: Core-Bond B73 used with BPO for gun application, B71/75 are
sprayable versions using MEKP, (page 2). Core-Bond meets cleavage strength requirements for balsa and foam cores.
November 2013
Page 1 of 2
ATC Formulated Polymers Inc.
3228 South Service Road, # 213
Burlington, Ontario L7N 3H8
Tel: 905-681-8112; Fax: 905-681-1535
www.atc-fp.com
Plant: ATC Formulated Polymers Inc.
2400 Canadian Street, # 303
Drummondville, Quebec J2C 7W3
Tel: 819-477-1752; Fax: 819-477-8815
CORE-BOND B70
Technical Data Sheet
Color White
Density 0.68 -0.72 g/cc (5.75-6 lbs./gallon)
Compression strength 1800 psi
Deformation before rupture 9.8%
Shrinkage Less than 1%
Thixotropy Non-sagging
Capillary absorption None, non-porous surface
Water absorption Less than 1%
Viscosity 108,000 – 124,000 cps
General Properties
Installing a core material with Core-Bond is a 2-part system consisting of Core-Bond, which is catalyzed with a BPO/5 (50% benzoyl
peroxide) green paste catalyst, and a GP or ortho/DCPD laminating resin for priming the foam or balsa core, which is catalyzed with an
MEKP catalyst. The catalyzation instructions below, for a 50-55 minute gel time, are based on a 100 gram mass. For an under the core
gel time, add approx 5-10 minutes. The Core-Bond and priming resin should gel at about the same time. Verify this under shop condi-
tions using the Core-Block Test (refer to ATC Core-Bond Manual).
Core-Bond B70 Catalyzation
Green BPO Paste Catalyst. 50% – for 50-55 minute gel time in a 100 gram mass*
Polyester-based Core Adhesive for Foams and Balsa
* Allow an addtional gel time of approx 5-10 minutes in the core installation (Core-Block Test). Please adjust gel times for Core-Bond and
the Priming Resin to shop conditions using this chart as a guideline. Chart based on B70 (0.7 g/cc) and BPO/5 (1.15 g/cc)
e-mail: sales@act-fp.com
Core-Bond is a trademark of ATC Formulated Polymers Inc.
Temperature
F C
55 13
60 16
65 18
70 21
75 24
77 25
80 27
85 29
90 32
95 35
Core-Bond B70 R
(Regular Version)
Core-Bond B70 S
(Summer Version)
Core-Bond B70 W
(Winter Version)
% BPO
(by weight)
cc/Gallon
(3.78 l)
gr/Gallon
(3.78 l)
3.30
2.50
2.10
2.00
1.75
1.45
74.0
56.1
47.1
44.8
39.2
32.5
87.3
66.2
55.6
52.9
46.3
38.4
% BPO
(by weight)
cc/Gallon
(3.78 l)
gr/Gallon
(3.78 l)
% BPO
(by weight)
cc/Gallon
(3.78 l)
gr/Gallon
(3.78 l)
3.10
2.50
2.10
1.95
1.75
1.50
69.5
56.1
47.1
43.7
39.2
33.6
82.0
66.2
55.6
51.6
46.3
39.7
3.50
2.60
2.15
1.85
1.50
78.5
58.3
48.2
41.5
33.6
92.6
68.8
56.9
49.0
39.7
November 2013
Page 2 of 2
Technical Data Sheet
NOTICE: All precautionary labels and notices should be read and understood by all supervisory personnel and employees. Consult OSHA and govern-
ment regulations for additional safety and health information. Purchaser is responsible for complying with all federal, state, or local laws and regula-
tions covering the use of this product. The information contained herein is correct to the best of our knowledge. The recommendations or suggestions
contained in this bulletin are made without guarantee or representation as to results. We suggest that these recommendations and suggestions are
evaluated in the purchasers laboratory prior to use. Our responsibility for claims arising from breach of warranty, negligence, or otherwise is limited to
the purchase price of the material. All values can be revised due to on-going testing and are subject to change without notice.
ATC Formulated Polymers Inc.
3228 South Service Road, # 213
Burlington, Ontario L7N 3H8
Tel: 905-681-8112; Fax: 905-681-1535
www.atc-fp.com
Plant: ATC Formulated Polymers Inc.
2400 Canadian Street, # 303
Drummondville, Quebec J2C 7W3
Tel: 819-477-1752; Fax: 819-477-8815
e-mail: sales@act-fp.com Core-Bond is a trademark of ATC Formulated Polymers Inc.
BPO Catalyzation with the calibrated Dispenser
Priming the Core
Core Installation
Storage/Shelf Life
Please refer to the ATC Core-Bond Manual for proper installation procedure and contact an ATC representative for vacuum-bagging
recommendations specific to the core being used. For temperatures outside the listed range, consult ATC. Stir Core-Bond well with large
blade mechanical mixer before and after adding BPO cata
lyst. Also stir BPO catalyst before use.
Spreading Core-Bond with a notched Trowel
Core-Bond should be spread with a notched trowel, the ideal configuration has 1/4 (6mm) equilateral triangles. For contour-cut foams or
balsa, as additional material maybe needed to fill the kerfs that open up in a curved section. The stainless steel ATC trowels are available
through your ATC distributor.
Core-Bond B73 for Gun Application with BPO Catalysts
The pumpable version of Core-Bond B70 is Core-Bond B73, supplied in drums, to be dispensed with internal mix equipment. Dispension
guns are supplied by Magnum Venus Products, www.mvpind.com; GS Manufacturing, www.gsmfg.com; Glas-Craft, www.glascraft.com.
Core-Bond B73 uses a 40% BPO catalyst (please contact us for details about the catalyst). Please refer to Core-Bond B73 Technical
Data Sheet.
Core-Bond B71/75 sprayable Versions with MEKP Catalysts
There are two sprayable versions of Core-Bond for use with a MEKP catalyst, Core-Bond B71 (18-24 minute gel time) and Core-Bond
B75 (35-45 minute gel time). Please refer to Core-Bond B71/75 Technical Data Sheet.
For maximum shelf life, store Core-Bond and BPO catalyst in a cool, dry area, maintaining the temperature between 10 – 20 C (50-70 F).
This would also extend the gel time in warm climates as the material starts out cool when used. Avoid storing in heat or direct sunlight. If
stored in a cold area, let Core-Bond reach shop temperature. The shelf life is 12 months under recommended storage conditions. After
this time a gel time test is recommended to assure useability. Do not store BPO catalyst above 80 F.
Priming the core is a necessary step which achieves the required bond strength.The resins used are normally low styrene content (below
40%) medium to high reactivity GP/ortho resins, ortho/DCPD blends. Iso and vinylester resins may not work as well, especially in higher
temperatures, as they can force styrene or styrene vapors into foams or balsa causing bond line undercure. To check the priming resin
suitability, make a Core-Block Test as described in the ATC Core Bond Manual . ATC also supplies a designated priming resin, (which
can also be used as a core surface sealing – or hot coating resin). This is recommended when hot and humid shop condition exist. The
priming resin needs to be catalyzed for a 15 minute gel time in a 100 gram cup for the temperatures listed in the Core-Bond catalyst
chart. Please follow the MEKP catalyst levels recommended by the priming resin manufacturer. The objective is for the priming resin to
catalyze in a thin film on the core material surface at about the same time as the Core-Bond. Refer to the Technical Data Sheet for the
ATC Priming Resin.
The dispensers are calibrated with a 10-60 cc scale so that one gallon (3.78 liters) can be catalyzed at a time. The dispensers are made
from polyethylene and can be cleaned with a soft cloth or paper. DO NOT LEAVE IN ACETONE, STYRENE, MEK, OR OTHER SOL-
VENTS. Dispensers are available through your ATC distributor.
CORE-BOND
B70