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Plastic refractories are delivered in an unfired and formable condition. They are installed by use of a pneumatic
hammer to form the refractory mass. These products are used both for original installations and for patching. Plastic
refractories can be used in many varied applications and locations because they are essentially formed by the installer
to fit the specific use area.
Important aspects for the successful installation and use of plastic refractories include ramming equipment, ramming
technique, forming, trimming, venting and curing. While each situation may have some special considerations the
fundamentals in brief are as follows:
- Pneumatic ramming tool with 2.5 to 3 inch convex aluminum head. This allows optimum knitting of the plastic
refractory slabs required to fill the required space. Care needs to be taken in the amount of ramming (the
plastic refractory already has density, the installation process is to knit the individual pieces together)
and direction of ramming (toward forms, ports and anchors is recommended).
- Support forms may be required for roofs, arches and ports as the plastic could slump during installation.
These forms need to be sturdy and well braced to prevent flexing while the full weight of the refractory
plastic is supported.
- Surface finishing is required after the ramming is completed. This includes trimming (use of a trowel or
spade to remove excess and shape but not smooth the surface) and peening (ramming around roof anchors to
attain a better seal).
- Venting the plastic refractory to allow for escape of steam during the curing process. Generally, this
entails driving a 1/8 inch rod through 2/3 of the rammed body thickness on 8 to 12 inch centers.
- Curing or heat-up should begin immediately after installation. Check specific procedures for the installation
location and specific material prior to beginning the job as proper curing is important to optimum service
performance.
Refractory plastics can be used to patch or repair worn refractory areas whether they were originally brick castable
or plastic. For the best results, the worn refractory should be removed back to a sound surface, removing loose
material and preferably providing V-shape surfaces that will allow good bonding of the patch to the original refractory.
A bonding mortar coating aids in achieving a lasting patch with good adherence.
Resco manufactures many types of plastic refractories designed for original installations and patches and for
compatibility with the application conditions.
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