How to Repair a Worn Shaft Using Injection

In our previous blog post, How to Repair a Worn Shaft with Belzona 1111, we introduced a shaft repair using forming techniques, an epoxy paste-grade material (Belzona 1111) and a pre-fabricated stainless steel former. Unlike conventional methods (for example, welding, metal spraying, etc.), repairing a shaft with a polymeric metal rebuild compound allows you to carry out the repair in situ, without the need to disassemble the equipment. Additionally, Belzona metal rebuild materials extend the life of equipment and protect against corrosion, abrasion, and impact.

In this post, we demonstrate a different technique of a worn shaft repair that utilizes an epoxy coating, Belzona 1321 (Ceramic S-Metal), applied through injection ports. This method of a shaft repair is suitable for situations including, but not limited to:

• restricted access to the shaft
• confined workspace
• pre-installed former
• limited personnel carrying out the repair

Additionally, since the recommended material to be used with this technique is a fluid grade, it exhibits high compressive strength crucial for the functionality of the equipment. The application and installation by injection is easy and does not require hot work. The ceramic fillers in Belzona 1321 make it exceptional for erosion and corrosion protection, and thus for the longevity of the rotating equipment.

3D Printed Shaft Former

Traditionally, stainless steel formers have been widely utilized for repairs on shafts. With 3D technology becoming a game changer in the manufacturing world, it is simplifying how repairs can be done. Why 3D technology? Shorter lead time, design flexibility, and lower costs. For this demonstration, we used a 3D former printed so we could compare its performance to that of a stainless steel former.  As a result, it performed as expected and helped carry out the application smoothly.

This is not our first attempt at bringing in 3D printing technology to assist with Belzona repairs. In one of our previous blog posts, How to Repair a Live Leak with Belzona 3D Mesh, we demonstrated how to stop a live leak utilizing a 3D printed mesh.

For this repair, we used Belzona 1321 (Ceramic S-Metal), a 3D printed former, Belzona 9111 (Cleaner/Degreaser), Belzona 9411 (Release Agent), an injection gun and a few tools from our machine shop. Injection and vent ports had been drilled on the former prior to the start of the application. We cleaned the repair area, applied release agent to the internal surface of the former and the area surrounding the repair area. Then, the former was clamped around the shaft and secured in place with bolts. Next, Belzona 1321 was thoroughly mixed and poured into an injection cartridge.  Using an injection gun the mixed material was injected through the injection port on the bottom of the former. The exuded product was carefully removed. Once cured, the former was removed and the repair area was smoothed out with an emery cloth to eliminate any sharp edges.