{"id":925,"date":"2010-10-19T21:35:06","date_gmt":"2010-10-20T02:35:06","guid":{"rendered":"http:\/\/www.rpwoodwork.com\/blog\/?p=925"},"modified":"2010-10-21T19:22:41","modified_gmt":"2010-10-22T00:22:41","slug":"improving-gimlets-yes-they-can-work","status":"publish","type":"post","link":"https:\/\/www.rpwoodwork.com\/blog\/2010\/10\/19\/improving-gimlets-yes-they-can-work\/","title":{"rendered":"Improving gimlets – yes, they can work"},"content":{"rendered":"

\"\"<\/a><\/strong><\/p>\n

Gimlets can be handy tools<\/strong> especially when you need to bore a small hole and the usual drilling tools cannot fit in a tight space. I usually find myself using them if I\u2019m in a jam<\/strong>, meaning that I need to drill a hole that I should have made at an earlier stage in construction. I find gimlets useful in small diameters, from 5\/64″ to 5\/32″, and mostly use them to pre-bore for screws.<\/p>\n

The problem is that gimlets do not work very well – they tend to split the wood<\/strong>. I am referring to the commonly available gimlet with a screw point followed by drill flutes further up the shaft. Lee Valley<\/a>, Highland Hardware<\/a>, Garrett Wade<\/a>, and others sell what appears to be the same set of seven for about $14-$15.<\/p>\n

For the record and to distinguish, there are other, fussier-looking, more expensive types of gimlets<\/strong> that more resemble a tapered drill bit, some meant to be used in a brace, that are less widely available and not dealt with here. There is also a Japanese gimlet,<\/strong> the kiri<\/em><\/strong>, that resembles a miniature sharply angled spade bit on a tapered dowel handle that is rotated between the palms to bore a hole. Still another tool altogether is the very useful brad awl or bird cage awl<\/a>.<\/p>\n

The design of the common gimlet, pictured above,\u00a0causes the screw threads to feed aggressively<\/strong> into the wood and squeeze past the wood fibers<\/strong> while doing little, if any, actual severing of the fibers. It\u2019s not really much improvement over just pounding a round nail into the wood.<\/p>\n

However, consider\u00a0the design of\u00a0auger point screws, shown below<\/strong>,\u00a0such as the type used for pocket-screwed joints. These\u00a0break some wood fibers<\/strong> as they are driven and so reduce splitting. They do not, however, appreciably clear chips from the hole because the screw threads are not designed to do that. What if<\/strong> the gimlet screw point was altered to mimic an auger screw point so it could cut fibers, and pass the chips onto the drill flutes so they could be cleared?<\/p>\n

\"\"<\/p>\n

I made this alteration to the points on my set of gimlets.<\/strong> I found that the edge of\u00a0a Japanese feather saw file<\/strong> (hatsuke-yasuri<\/em>) did the job quickly and well, even on the 5\/64″ gimlet, and better than a diamond paddle or a triangular Western saw file.\u00a0I cut two slots on each gimlet, 180\u030a<\/span> apart.<\/p>\n

\"\"<\/p>\n

The 75 mm “full cut” Japanese file<\/a> that I used:<\/p>\n

\"\"<\/p>\n

Does it work?<\/strong> Yes, fairly well and certainly a big improvement<\/strong> over the unaltered gimlets!\u00a0The modified screw point cuts some fibers, makes boring easier, and produces some chips, although the chips don\u2019t get cleared very well by the drill flutes. To compensate, I simply periodically pull out the gimlet<\/strong> to clear chips. Splitting is virtually eliminated.<\/strong>\u00a0<\/p>\n

This simple modification turns a frustrating tool into a life-saver in a bind. <\/strong>In fact, I\u2019ve gone from almost having given up on these tools to valuing them enough to make a nice little holder for them<\/strong> which attaches to the inside of a door of my hand tool cabinet.<\/p>\n

\"\"<\/p>\n

Addendum: (10\/21\/10)<\/strong><\/p>\n

By “fairly well” I mean<\/strong> that gimlets still have their drawbacks. They are, after all, very simple tools that are substitutes for more mechanically sophisticated tools that are preferable – like a drill. So, in the context of a gimlet, I think I can say that this modification makes them work, here goes, “well!”<\/em> <\/strong><\/p>\n

It helps to use the Japanese file to create a clean slot with an approximately 90\u00b0 attacking edge<\/strong>, as pictured. This edge meets the wood aggressively and breaks the fibers. A sloppy “V” groove would have, in effect, a relaxed “rake” angle to meet the wood and thus be less effective.<\/p>\n","protected":false},"excerpt":{"rendered":"

Gimlets can be handy tools especially when you need to bore a small hole and the usual drilling tools cannot fit in a tight space. I usually find myself using them if I\u2019m in a jam, meaning that I need to drill a hole that I should have made at an earlier stage in construction. […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-925","post","type-post","status-publish","format-standard","hentry","category-tools-and-shop"],"_links":{"self":[{"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/posts\/925","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/comments?post=925"}],"version-history":[{"count":11,"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/posts\/925\/revisions"}],"predecessor-version":[{"id":941,"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/posts\/925\/revisions\/941"}],"wp:attachment":[{"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/media?parent=925"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/categories?post=925"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.rpwoodwork.com\/blog\/wp-json\/wp\/v2\/tags?post=925"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}