Spiral router bits for dovetail jig

[CWatters]

Making a jig for cutting through dovetails on a router table. Works well but it seems very easy to get tear-out. Particularly on one side of the cut as the blade is leaving the wood on that side.

Does anyone here use spiral cutter bits for this? Do they help?

Edit: Can you even get spiral dovetail bits?

 

[Rhossydd]

Edit: Can you even get spiral dovetail bits?

Not that I've seen.

 

[marcros]

could you not put a sacrificial piece on the side where the cutter exits.

I am sure that I have seen somebody using a tape of some sort too, although I cant recall where.

 

[StevieB]

Yup - just put a piece of MDF, ply or similar behind your workpiece to prevent tear-out. If you are doing repeat cuts on a fixed space jig then the backer piece doesn't really need changing. If you are variable spacing or different sized cutters however then you will need to replace the backer when you have used it.

Steve

 

[CWatters]

Good idea thanks.