Hello friends. I apologize if this issue has been covered in the past.
The issue is, I can’t seem to be able to clamp knives with bevel that are gradually decreasing the thickness from the spine. In another word, the spine is the thickest part, and then the thickness decreases as you move towards the edge. As a result, I can’t keep the blades clamped at all.
Any suggestions?
Take a look at Clay’s page on Full Flat Grinds (FFG), and see if that answers your question.
If not, let us know! 
[quote quote=“mamun1024” post=7158]Hello friends. I apologize if this issue has been covered in the past.
The issue is, I can’t seem to be able to clamp knives with bevel that are gradually decreasing the thickness from the spine. In another word, the spine is the thickest part, and then the thickness decreases as you move towards the edge. As a result, I can’t keep the blades clamped at all.
Any suggestions?[/quote]
Post some pictures if you can.
I’m sure the team here will advise some workaround for you.
It can take a while to get good at it, but the foam tape trick Clay shows in that link will work.
Most of my knives are Spyderco with full flat grinds and distal tapers. I have managed to clamp and sharpen them all. If you are having consistent problems still, make sure you don’t have one of the older defective vice jaws. If your vice arm is bent at all, the clamping will not work properly. I had this problem and it was extremely frustrating until I realized the thing was bent.
Would it be a good idea to put this topic on the WiKi? At least a link to Clay’s video. Or make it a sub topic under Techniques and Sharpening Strategies? If Reed Knives have a topic I think FFG deserves one.
The wiki is open to forum members… so feel free to head over and add to it!