The Framers Forum

how do I tell when a blade set needs sharpening? I have a spare sharpened set and I will use the company that I purchased my equipment from to sharpen them (@londonletterpress), they did suggest that the ideal scenario is to have 3 sets of blades, one on machine, one sharp spare and one set at sharpeners, but as my volume is low at the moment they said that 2 sets should be ok for the foreseeable, he told me that I would notice when they are not sharp enough and it depends on volume and also materials being cut, do I let them get completely blunt or slightly blunt?
Danny

A sharp blade is fundamental to getting a really good result.

So my advice would be to keep them sharp, otherwise if you let them go until they are really blunt, half of your production will be sub-standard. That said, how will you know when it is time to change them? It's not easy to give an answer, but this is how I do it.

I am a one man low/medium volume framer probably averaging 30 frames a week. I have 3 sets of blades, so I always have a sharp set ready to put on. I cut all types of moulding, but mainly obeche and oak. Last year I had 10 blade sharpens done, so bearing in mind I had almost 8 weeks of holiday that's just over 4 weeks on a set of blades before sharpening.

The signs that I look out for
1) The blades are giving more resistance through the wood
2) Tearing the wood (particularly obeche)
3) Back of mouldings breaking out
4) Vertical lines on the cut edge of the moulding where there is a nick in the blade
5) Imperfect joints (if the blade is blunt it can bruise the wood as it attempts to cut it)

If I suspect the blades need sharpening I will always test on a couple of other mouldings if I am not sure (some obeche is so soft even brand new blades will tear it!). You can also try cutting a sheet of paper, or a tissue to see how cleanly it cuts.

When you do have the blades sharpened, be sure to have them hollow-ground by a company that specialises in Morso blades.

Thanks Jeremy
That advice from a professional is very much appreciated, is it worth having a standard material for testing the blades on, something that you know cuts well with sharp blades. When we have trouble with hot foil printing we have a go-to paper and a go-to foil, if a job is giving problems with a certain media/foil combination we then use our go-to products and if it prints fine we then know it is either the other media/paper/card stock or the foil, process of elimination

I have only ever had two sets. Some moulding will dull the blades faster than another. Oak/Ash is tough on blades and also
needs a sharp edge to get a good cut. So if you are using a lot of this timber then you need to swap blades more frequently.

Also, certain mouldings with a rock-hard coating will dull blades after one slice. There are some that need a saw.

I go along with Gesso&Bole has said, and what to look out for, plus I push the head of the Morso back as far as it goes, then holding a bit of paper, I pull this up the blades (very carefully ) if it doesn't get cut very easy, then it's time to get the blades sharpened