# Tube file truing



## retrobuilder (Feb 8, 2018)

Working on a Columbia which appeared to be stripped of paint long ago...

*Steel is in good condition howver to better true the high visible tubes I am using a flat file to rasp the tubes to better true the shape, remove minor bumps, inperfections and minimize need for much primer filler. Can also use a rat tail file.for concave tubes.*

Power tool sanding is often all to much abrasion and flattens round tubing (although I do that at times)

BTW- I first use 80 grit 1" wide sand paper to push/pull wrap the tubing for removing surface oxidation "particles" buildup.

I always use a chemical rust remover or converter to dereust into the metal pores..

Painting is 90% prep and 10% painting...cheers..


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## Craig Allen (Feb 8, 2018)

Keep in mind that the tubing has a wall thickness of about 1/16". Filing off too much and you end up with a frame that is structurally compromised. High spots are better off hammered in.


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## retrobuilder (Feb 9, 2018)

The material I mention is not dents,or bumps.

This is the raised rust oxide layers and the long raised forming ridges under .01".larger than the tube.

I am confident bthe tubing is structurally sound, 

A tube "bump" from damage would normally be brazed or mig welded this shaped,

*But you do express a worthy comment for peole who over use grinders to prep a frame. 
They often gring excessive flat spots into the round tubes,*

Cheers..


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