chopper engine

[painter123]

I am building a custom chopper I have a new ultma 113 that I have taken apart and polished the cases on it but I cant seem to get the jugs and heads.
What do I need to do to get down between the fins.

[andybrown]

Hi, use what we call in the uk as a "razor buff" Rather than the usual thickness of a polishing mop being half inch or 1 section, these are very thin, 1/8 " or 3.1 mm, they will get in-between the fins and do the bottom and the walls of the fins, don’t be scared to give it some abuse to make it work / force the buff where you want it to go.

Use a coarse and or medium compound on it, then finish with the usual soft loose mop with some fine blue compound.

Hope that helps,

regards,

[painter123]

Thanks so much I cant believe there was no posts for so long.
On one part of the jugs there is a dip I just cant get what do I use on it!!!

[andybrown]

No worries, my pleasure. Can you post a pic of the area your talking about, not familiar with "the jugs" we may call them something different in the uk. Regards,

[painter123]

Ok its the shadow area in one pic you can see some casting

[andybrown]

Ahh i see, ok, I would firstly sand the fine edges of the fins on the outside, the edges that your hands would touch if you grabbed hold of the part, looking at that pic i would use a 240grit disc on a rotating pad, (not a d.a. pad, just a pad that spins round and round, tilting the pad and using half the pad as the contact area if you see what i mean) Then repeat with 400 grit.

Then id get three 8" razor buffs (8" looks like they will go right to the bottom of the fins) (like very thin polishing mops) and id go straight in with a cutting compound on one of the buffs, loading the buff regularly as with them being thin they don’t hold much compound, and hold the part so you can slide the buff in-between the fins, id probably re-load the buff twice or maybe 3 times per fin. Then also tilt the part right and left only maybe 10 or 15 degrees each way so the razor buff also polishes the walls of the fins (if you see what i mean?) Then use the cutting compound on a standard sisal mop for the edges that you have sanded. Then repeat, new / clean razor buff with a medium compound, then again on the edges with a normal close stitch mop with the same medium compound. Then repeat a third time with the fine compound on a new / clean razor buff, and finally go over the outer edges with the loose / soft mop and a fine compound (go with the direction of the fins not against them)

That’s how i would approach that job and the only way it looks possible to me,

Hope that helps, any further questions please ask,

regards,