Premature bolt wear...
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Premature bolt wear on VCOM spool engine

New Member
Joined: 1 year ago
Posts: 1
Topic starter  

Hey TechPB’ers old and new!

Quick question about a Bob Long since I know y’all love them here.

Recently purchased an OG BL TRex with a spool engine which was brand new.

During setting pressures and chrono’ing I shot about a hopper through it and took out the engine to lube and noticed some of the anno had come off the red bolt tip in a 1/2 inch rectangle exposing the silver underneath.

I checked to make sure the bolt wasn’t over tightened/loose on the ram and it seemed finger tight with my allen key.  Also checked the brass piece held by Green loctite wasn’t coming off.  Is this wear normal after such little paint? If not does anyone know any fixes I could try?

Thanks for the help in advance!

Active Member
Joined: 1 year ago
Posts: 13

Is it actually scratching the breach and the bolt at the same time? 

Moving parts rub the anodizing off of parts due to friction. Bolts and O-rings are usually made from softer materials. The body of the marker is usually harder aluminum while the bolt and o-ring are generally softer materials.  The wear will be minimal as long as it's not gouging the bolt tip and body at the same time. You can usually rub your fingernail across the bolt to feel gouging lines. What I experienced coming from a long-time use of bob long markers is that red anno comes off but does not affect the performance.  My insight bolt was red and after a while, it started rubbing off. To reduce that wear on the body and anno you want to clean that area often. Most BL markers you want to lightly coat, meaning very light, these bolt tips with Tri-flow.  You can get some from a local bike cycling shop. I use it on other bolts as well. Made for things like bike chains and exposed moving parts like paintball marker bolts. Bob Long markers in the past like Dow 55 as well to seal them up.