Scribing plastikard for wagon sheeting

[Dog Star]

Many moons ago I modified a scraperboard tool to produce a scriber for producing the plank grooves in plastikard wagon sides - the tool had a V-shaped tip with each side of the V stoned to a cutting edge. The inclusive angle at the tip was of the order of 15 degrees. In use this tool would remove plastic from the flat side, as a thin curl, rather than just push material to one side as does a knife blade. Whereas a knife blade raises a burr in the surface of the sheet the scraperboard tool would produce a neat groove without a burr.

My initial tool has gone AWOL and so I have tried to produce a second cutter... without the success of the original. The current tool removes a thin curl as before and, unfortunately, raises a small burr. I have tried to remove the burr, using an emery board, with not a lot of success because the raised material prefers to go back into the groove.

The plastic sheet is 10thou thick so running the replacement tool along the groove more than three or four times leads to the plastic cracking.

Given that using thicker plastic sheet is not an option, I suspect that the cutting edges of the replacement tool are not good enough, maybe without sufficient relief on the back face. Any suggestions as to possible alterations to the tool?

thank you, Graham

 

[JimG]

Graham,

Possibly try a larger angle on your cutting tip. I've just checked my Olfa cutter blade and it has an angle of around 60 degrees - maybe more. This might reduce the tendency to plough a furrow.

Jim.

 

[Steph Dale]

Graham,
I've never really found a satisfactory solution to the issue you describe with home-made tools. For the sake of a couple of quid I'd get an Olfa or Tamiya plastic cutter and have done with it. A possible alternative is to buy 'laminate cutter' blades for a Stanley knife, although I've found that these need a few passes over an oil stone to get them to work perfectly on styrene sheet.
Steph

 

[AJC]

While I have a scraperfoil tool, and have used it to good effect on thicker sheets, I never use anything more sophisticated that a Swann Morton 10A scalpel; one pass, conventionally, but very lightly followed by a second, perpendicular to the straightedge. There will inevitably be a little burring but it's easy enough to clean up using the same blade, run across the surface a bit like a plane at about 30 degrees from the surface.

Adam