I have a '33 Ford truck dash, with the factory holes, which I'd like to install some basic SW gauges. The center hole is 2 3/4" & the other two are 1 7/8". The gauges, which I do not yet have, always specify 3 1/4" & 2 1/6" respectively. I restored the whole dash & always "***umed" that the holes were the same size as the gauges. Right. I'm sure that everyone else runs into this same problem, so I was wondering if anyone has any special tricks to enlarge the holes to accept the gauges. Do you just grind away & hope that the bezels cover the new (uneven) openings?
C-clamp some 1/4" bar across the back of the opening, drill a hole dead center to the old gauge opening and use a hole saw to cut the new size most hole saws have the arbor for a 1/4" drill bit....use rod instead of a bit to keep from opening up your center hole....go slow! you could also clamp the dash in a drill press or mill with wood under it and just center the holesaw with no pilot hole good luck Zach
also, i made this thing....its adjustable to almost any size if you use a full thread bolt you would need to clamp the dash in a press or mill to use it...but its a simple tool with a sharpened drill bit for a cutter just incase you cant find the correct hole saw size
KISS (keep it simple stupid) wins again. Great idea Zack! And broken drill bits are easier to find than holesaws around my place! Waste not want not
whip up a couple of these on the lathe. use the appropriate hole saw with a 1/4" rod inserted for the drill bit. perfectly centered and you dont even have to take out the dash.
I have backed em up with masonite or thin plywood. You can glue it to the backside of the tin. I holds well enough for the holesaw to get a good start in the tin then you dont care!
For the smaller holes, like going from 2" to 2 1/16", I have used a sand paper flapper which come in different sizes. They have a pipe thread but I just used it on a hole saw arbor without a bit but it will wreck the non-pipe threads of the arbor if you do so do not plan on using it again for hole saws.
These are pretty expensive. They are for electricians to punch conduit knock outs in NEMA boxes so be carefull when you select the size as one for a 2" conduit knock out is not exactly a two inch hole. They should list the actual hole size it makes.
Thanks for all of your ideas...it always amazes me how many different ways there are to do the same thing. I'm pretty good with the basic hole saw (I did 18 holes in my seat backs), so I'll probably do the Zach/T-Man method. The dash is not installed, so I should be able to get it done.
Yet another way is to use some plywood on the front . Cut the hole you want in the plywood square , clamp to dash then insert your hole saw . You won't need a pilot bit as the wood acts as a guide . Large holes over 2" cause the saw blade to grab and pull to one side . On the larger holes , especailly the size of a gauge , this can snap the pilot bit then you're in trouble . If clamping is going to be difficult you can use another piece in back bolting them together . Without the pilot bit this is easy to do . If you have the time put a little fast set silicon caulking on the plywood and let sit over night . This will help insure thar it doesn't move whilst drilling
I tack weld a piece of sheet metal to the back side then go at it with the larger hole saw. When you cut through the piece that is tacked on comes loose with it.
As an electrican,I use those punches pictured above all the time.They will cut a very clean hole in thin sheet steel especially when they are new and have a sharp edge.For accurate layout,scribe the opening circle,then line up the punch carefully with the smaller male punch half .On softer thicker metal,the punch may flange over the edge slightly.This doesn't matter on electrical stuff,but it might matter on a dash board.If you have any doubts,make a test punch in a similar piece of metal before ****ing up your dash panel.
some holesaw arbors have longer threads, if you can find one of these then screw on the holesaw size you need. then screw on the smaller holesaw to fit the existing hole. you will have 2 holesaws on the arbor at the same time. works great.
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