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DERAKANE Fabricating Tips - 34 / 56 Pages

Inspecting a laminate
Barcol hardness values are used to indicate the completeness of resin cure in FRP laminates. To test for Barcol hardness, use the Barcol Tester #934.1* to take readings on both the inside and outside surfaces of the part (10 to 12 readings in all). Reject the highest and lowest readings, and average the remaining values to get the Barcol hardness value.
Key points
• Calibrate the Barcol Tester with both high and low hardness discs, and check it frequently.
• Use the Barcol Tester at room temperature (about 77°F [25°C]).
• When using the tester, keep it level. Be sure the point is perpendicular to the laminate surface.
• Clean or replace Barcol points frequently.
• Be sure to take measurements at secondary bonds, such as flanges and internal connections. Values at these points are critical.
• Laminates with high glass filling may give abnormally high Barcol values when the point hits glass.
• Contacting a synthetic veil may cause a drop of 2 to 3 points.
• Improper catalyst ratios may cause low Barcol readings.
• Incomplete catalyst mixing may cause widely varying readings.
• Heavy residual wax on the surface will cause low Barcol readings. Lightly sand off 1 to 2 mils of wax and test again.
Most FRP inspection, other than hardness checking, is visual, because physical testing is generally destructive. However, defects can be identified by observing the finished construction. The list of defects found on pages 33-35 can be used to help identify problems and correct fabricating techniques.
Table 9.1 - Typical Barcol Tested Hardness
Hardness Values
DERAKANE 411 Resin
DERAKANE 441-400 Resin
DERAKANE 470 Resin
DERAKANE 510 Resin
DERAKANE 8084 Resin
* Product of Barber-Coleman Company ** RT = Room Temperature
This bulletin contains tips and suggestions, but no warranty, expressed or implied, is given; fabricators are advised to determine suitability as to any product, additive, process, formula, ratio, or end-use through their own expertise or tests.
DERAKANE Fabricating Tips
  1. P. 1

  2. P. 29

    SECTION 8 POSTCURE For a service temperature below 100C/210аF: A postcure may extend the service life if the operating temperature is within 20C/40аF...
  3. P. 30

    COMPOSITE POLYMERS SECTION 8 APPLYING A TEST PATCH >It is good practice to apply a test patch to check the soundness of the prepared surface before...
  4. P. 31

    SECTION 8 Step 3: Apply chopped strand matStep 4: Apply surfacing veilStep 5: Inspect and repair the liningStep 6: Apply topcoat >Cut two layers of...
  5. P. 32

    COMPOSITE POLYMERS SECTION 8 LINING AN FRP SURFACE Step 1: Sandblast or grit blast the surface Blast the surface until sound FRP is exposed. The FRP...
  6. P. 33

    SECTION 8 EPOXY VINYL ESTER RESIN ANCHORS FOR CONCRETE For service temperatures of up to 180F (82аC), DERAKANE8084 epoxy vinyl ester resin canbe...
  7. P. 34

  8. P. 35

    SECTION 9 Defect Nature Possible Cause Air bubbles, voids Air entrapment in and between plies; non-interconnected spherical voids.Whipping action during...
  9. P. 36

    COMPOSITE POLYMERS SECTION 9 Defect Nature Possible Cause Delamination Separation of layers.Poor glass saturation. Dirty surface. Toohigh glass content....
  10. P. 37

    SECTION 9 Defect Nature Possible Cause Pit or pinhole Small regular or irregular crater on surface, usually with nearly equal widthand depth.Air bubbles...
  11. P. 38

    COMPOSITE POLYMERS SECTION 10 Other processing techniques As we stated in Sections 1 and 2, FRP is made with reinforcement material, such as glass...
  12. P. 39

    SECTION 10 ProductPercentageOz per 55-gal drum Part A, Drum DERAKANE411-45 ResinDimethylaniline 100%0.1-0.36.3-18.8 Note: Shelf life is several weeks....
  13. P. 40

  14. P. 50

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