SR648 Natural Rubber Lining

This natural gum rubber lining material provides chemical and abrasion resistance.

Lining Specifications

Lining Code: SR648

Type: Natural

Tie Gum: Without Tie Gum

Properties: Durometer 40 +/- 5 – Natural, Tan Gum, with No Tie Gum with chemical and abrasion resistance properties. FDA compliant.

Note: Natural rubber will “weather check” (prematurely degrade) if exposed to sunlight, ozone, and oxygen.

Primers and Adhesive System:

  • One coat Chemlok® 289 on Metal
  • One coat Chemlok® 290 on Metal
  • One coat Chemlok® 286 on Metal
  • One coat Chemlok® 286 on Lining

Cure Time and Temperature:

Cure for thickness up to ¼”

Pressure, Saturated Steam (Autoclave)1 1/2 hrs. @ (25 psi) 267°F (121°C)
Internal Steam Cure2 1/2 hrs. @ (15 psi) 250°F (121°C)
Atmosphere Steam Cure24 hrs. @ 212°F (100°C)

Note: All reference to cure psi represents gauge pressure.

**Cure times may require tunings to compensate for low temperatures, heavy metal thicknesses, and other anomalies. Contact SRR Technical Department for recommendations on lining thicknesses over ¼”.


Ideal storage temperature is 50°F not to exceed 85°F and shelf life is 180 to 45 day range respectively.

Depending on storage conditions it may be possible to use rubber linings beyond shelf life. Please contact Salem-Republic Rubber Company for technical advisement before usage.

Designed Physical Properties

Tensile Strength PSIASTM D412
2500 min
% Elongation at Break
ASTM D412500 min
DurometerASTM D224040 +/- 5
Specific GravityASTM D2970.95
Adhesion to MetalASTM D42930 pli min

Skive: Closed

Repair lining: Same or SR648

Application Suggestions

  • Plying up lining thicker than 1/4″ is not recommended due to sagging during cure process.
  • Warming rubber to approximately 120°F will aide in applying and is recommended. 
  • Over-curing is possible, if temperature specifications and cure times are exceeded, resulting in reversion. 
  • Experienced applicators may have techniques which produce equal or superior results and by no means are SRR’s application suggestions meant to replace these proven techniques. As long as those procedures fall within industry standard lining application guidelines.

Standard Dimensions

RollStandard GaugeToleranceRoll GaugeStandard RollMaximum
A Roll.120+/-.05A Roll90ft96
B Roll.180
+/-.010B Roll60ft66
C Roll.240
+.010 or -.020C Roll45ft51
3/8” Roll.360
+/-.0153/8” Roll30ft33
½“ Roll.480
+/-.015½“ Roll23ft27

*Customer specific gauges and widths, other than standard, are available upon request. Please call Salem-Republic Rubber Company at 1-877-425-5079 with any questions or more information about our Custom Elastomeric Linings.