I've noticed a few rod blanks lately that when turned are far from being round. They seem to have "flat areas" on them, say...from mid-blank down to the butt. Not something that you'd notice much unless you spun the blank (even by hand in your hand) while holding it with the other hand. I'm wondering if these flat areas may make a blank less durable, or may cause breakage isssues later on?

DR

They weren't sanding correctly. Send them back. The flat spots create weak spots in the blank, or can anyway. They also affect the "spine" thing although that's not really the main issue here. You just don't want blanks that weren't sanded correctly.

Duane,
Be careful before you judge.
Depending on the blank - some blanks are made in a shape that is not round.
If the rod design is NOT round- it won't be round.

On the other hand, if the rod is supposed to be round - but you received a blank that is NOT round - send it back.

Take care
Roger

No blank is perfectly round
the trailing edge of the cloth 'flag' used to create the blank spirals around the blank and the overlaps create extra thickness to the blank. thise xtra thickness depends upon the thickness of the cloth and the number & direction of wrappings of different cloths types in the layout of the blank.
Most of the grinding is only done to remove the ridges of resin formed in the curing process & not removal of fabric..
This trailing edge & its spiral is easily seen in clear gloss finished blanks that are not tinted.
If you mark a blank straight line down from tip to butt & section the blank you will see that a thicker section of blank in cross section corresponds with this trailing edge & it spirals around the blank, slower at the tip & faster at the butt....................a necessary evil in blank manufacture with a tapering wall thickness.
DenisB

Daune I would call the manufacture, before making a judgment call. Without knowing the manufacture none of us can make a call on this one.
Good Wraps Bob

A blank that is very much oval when straight is going to be very weak on one axis and being flexed deeply on that axis could easily result in failure. How bad in this regard are you talking?

If the flat areas are just here and there, it's due to poor sanding, something that is still done by hand on a grinder/sander wheel by most manufacturers.


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Measuring the blank in question, the roundness varys from 0.1mm-0.2mm, basically one "side" if you will is smaller than the other and it's in a measureable amount. I dont want to disclose the maker, lets just say it's a very "top of the line" bass blank made here in the US. It does appear that the sanding could? be the issue. I've tested the blank under stress and it seems solid.

DR

Duanne call the manufacture
Good Wraps Bob