ConcoursMustang Forums

1st Generation 1964 1/2 - 1973 - Questions & general discussions that apply to a specific year => 1969 Mustang => Topic started by: ng8264723 on October 07, 2015, 09:17:02 PM

Title: Drop off holes
Post by: ng8264723 on October 07, 2015, 09:17:02 PM
My car had the drop offs replaced.  Does anyone have a diagram for the correct placement of the factory drains?
Title: Re: Drop off holes
Post by: carlite65 on October 07, 2015, 09:46:17 PM
what are you working on?? need more info please.
Title: Re: Drop off holes
Post by: J_Speegle on October 08, 2015, 12:04:33 AM
No diagrams or measurements - just pictures.

Two holes - one larger round with a small square hole above that - each side

One with the drain in place

(http://www.concoursmustang.com/forum/gallery/4/6-071015220301.jpeg)




One with it out showing the holes - sorry metal is a little deformed but best picture showing an unaltered or rusted out set of holes


(http://www.concoursmustang.com/forum/gallery/4/6-071015220402.jpeg)
Title: Re: Drop off holes
Post by: ng8264723 on October 08, 2015, 02:22:49 PM
1970Mustang SCJ
How do you make the holes?  Size etc?  I would think drill the bottom with a hole saw or use a green lee punch?  The top drill a hole then file until square?
Title: Re: Drop off holes
Post by: Bob Gaines on October 08, 2015, 04:51:07 PM
1970Mustang SCJ
How do you make the holes?  Size etc?  I would think drill the bottom with a hole saw or use a green lee punch?  The top drill a hole then file until square?
One way to get a similar non jagged square edge is with a electricians hole punch ,chassis punch ? I think it is called . in any event a electricians  tool. I believe it is used for electrical boxes,panels,etc.  Two halves that bolt together and fit inside each other to shear the metal and leave a smoother edge unlike a hole saw.   
Title: Re: Drop off holes
Post by: 67gta289 on October 08, 2015, 06:46:49 PM
If the panel is not mounted on the car yet, an "ironworker" (various makes/models) is the way to go, one example attached.  I've got one at work, with a plethora of die shapes and sizes.  You certainly won't be spending $10K for a couple holes, but you might know someone with access to a tool like this.

If it is in place on the car, as Bob mentioned there are two piece punches (with mandrel) that come in various shapes and sizes.  You drill a hole first for the mandrel (which is smaller than the die), and then torque down on the die, either with a ratchet (poor mans version) or with a hydraulic ram.   Electrical based tools are the most popular.  Google "Greenlee Hole Punch".  A sample picture is also attached.  The most common as you can imagine are for 1/2, 3/4, etc. conduit fittings, and they are round.  But there are many many sizes and shapes out there, you just need to look.

With a mandrel based tool, you really need to get the exact shape die.  With an ironworker, you can if needed use smaller dies and nibble away at making a larger shaped hole, making it much more versatile.
Title: Re: Drop off holes
Post by: J_Speegle on October 08, 2015, 09:05:07 PM
Of course the holes will not be seen once the car is together - wish the reproducers would just make them correct to begin with. Its just easier to make one size fits all and let the owner/shop deal with the details :(
Title: Re: Drop off holes
Post by: jwc66k on October 08, 2015, 10:22:16 PM
I've use this type of metal nibbler tool for more years than I wish to reveal. Available from Amazon -
http://www.amazon.com/Hand-Sheet-Metal-Nibbler-Cutter/dp/B000T5FV4Q/ref=sr_1_7?s=hi&ie=UTF8&qid=1444353033&sr=1-7&keywords=sheet+metal+nibbler
You need to drill a pilot hole big enough for the nibbler head, but smaller than the hole you need. It makes square holes easily, round holes are better made by a chassis punch (see Greenlee on e-bay). The biggest problem is drilling a pilot hole in an installed piece of sheet metal, a right angle drill adapter "works" sometimes.
Jim
Title: Re: Drop off holes
Post by: Brian Conway on October 09, 2015, 01:26:39 AM
Why not drill the holes as you proposed and do the carving on the rubber drain's square fitting ?  Brian