Drilling the Body for Winshield Wipers - What Drill Bit?

[Papa]

I'm ready to drill my body for the wipers and thought I'd ask if there is a preferred type of 5/8" bit that works best without chipping the body around the hole? I'm thinking a hole saw may be better than a standard bit.

[CDXXVII]

I just used a new, sharp 135 degree split point drill bit. Take your time and do not bear down on the drill. Very little pressure so that it does not dig in too aggressively. Put a couple layers of masking tape down first and securely clamp the windshield drill guide onto the body. I used a few C clamps. Hopefully not yet painted body.

I used this bit by Fastenal. No need to spend this much but I needed the bit for work related projects as well.
https://www.fastenal.com/products/details/0316242

As an FYI: Do not rely on measurements provided by the manual or with those you find on the forum. It is best to mount the body in it's correct placement and secure the windshield at your correct angle. Then mark your holes. Mine would have ended partially into the rubber windshield seal had I not moved mine forward about 3/16".

[Papa]

I just used a new, sharp 135 degree split point drill bit. Take your time and do not bear down on the drill. Very little pressure so that it does not dig in too aggressively. Put a couple layers of masking tape down first and securely clamp the windshield drill guide onto the body. I used a few C clamps. Hopefully not yet painted body.

I used this bit by Fastenal. No need to spend this much but I needed the bit for work related projects as well.
https://www.fastenal.com/products/details/0316242

As an FYI: Do not rely on measurements provided by the manual or with those you find on the forum. It is best to mount the body in it's correct placement and secure the windshield at your correct angle. Then mark your holes. Mine would have ended partially into the rubber windshield seal had I not moved mine forward about 3/16".

Thanks for the quick reply! My body isn't painted, but I also have not test fit it and have not mounted the windshield. I was planning on using the measurements from the manual to drill the holes, but may wait after reading your post. I did see that the MK4 directions are different than the earlier bodies. The MK4 has the holes 7/8" closer to the hood opening than the previous generations.

Dave

[Jeff Kleiner]

I've done a bunch of 'em...my method is to make six or eight 3/16" holes around the I.D of the jig then "connect the dots" and shape to fit the wiper box shafts using a small drum sander on the Dremel.

Jeff

[BEAR-AvHistory]

Just a thought - Do you really need the wipers? Don't think anyone in our group has them.

[Ron J]

Hi, I have good luck drilling holes in fiberglass, and sheet metal, using a step drill. They don't grab, and/or tear, the material like a twist drill bit. Step drills are relatively inexpensive on eBay or Amazon.
Ron

[ej95Cobra]

Just a thought - Do you really need the wipers? Don't think anyone in our group has them.

In VA, the wiper is necessary to pass the vehicle safety inspection. F5 Roadsters are registered as a 1965 model year and I have with standard tags (not antique). Since most of our driving is in good weather I just keep the wiper arms/blades in the trunk.

[Papa]

Just a thought - Do you really need the wipers? Don't think anyone in our group has them.

I won't pass a Colorado State Patrol inspection without them, which means I won't get a VIN and can't register the car.

[Papa]

Hi, I have good luck drilling holes in fiberglass, and sheet metal, using a step drill. They don't grab, and/or tear, the material like a twist drill bit. Step drills are relatively inexpensive on eBay or Amazon.
Ron

If the hole were just straight through, That would be my choice as well, but the angle of the hole is important and I don't think a step bit would work.

Picture1.png

[Papa]

I've done a bunch of 'em...my method is to make six or eight 3/16" holes around the I.D of the jig then "connect the dots" and shape to fit the wiper box shafts using a small drum sander on the Dremel.

Jeff

Thanks Jeff,

Any issues with the measurements in the manual or do you also suggest waiting until the body is on and the windshield is mounted to drill the holes as CDXXVII recommends?

Dave

[edwardb]

I've found a step drill actually works quite well. It gets the majority of the hole cut. Smoothly and without drama as mentioned. Then finish off with a round file, Dremel as Jeff suggested, or a sanding drum as pictured here. One of the sizes I have happens to be the exact size required. I use the jig to mark the location and size of the hole, and eyeball the angle as I work. But then do the rest by hand. I'm not sure most realize how easy the body glass is to cut, sand, etc. The size and fit of the hole isn't super critical.

I would recommend waiting until the body and windshield are in place before drilling. Just to make sure the location is exactly right. It's easy to do with both installed.

[karlos]

I won't pass a Colorado State Patrol inspection without them, which means I won't get a VIN and can't register the car.

Do you have a pointer to a regulation that requires wipers in Colorado? Not trying to be argumentative, but there hasn't been a safety inspection requirement in Colorado for many years. It's my understanding that the CSP inspection that needs to occur to get the car registered is primarily a walkaround for the purpose of establishing a VIN. Many local Cobra owners I've talked with tell me that the officer barely looked at the car. But these things tend to be a moving target so if something's changed it would be good to know now rather than later.

Thanks.

[Papa]

Do you have a pointer to a regulation that requires wipers in Colorado? Not trying to be argumentative, but there hasn't been a safety inspection requirement in Colorado for many years. It's my understanding that the CSP inspection that needs to occur to get the car registered is primarily a walkaround for the purpose of establishing a VIN. Many local Cobra owners I've talked with tell me that the officer barely looked at the car. But these things tend to be a moving target so if something's changed it would be good to know now rather than later.

Thanks.

Karlos,

Here is the specific Colorado statute:

C.R.S. 42-4-227


COLORADO REVISED STATUTES

*** Current through all laws passed during the 2017 Legislative Session. ***

TITLE 42. VEHICLES AND TRAFFIC *
REGULATION OF VEHICLES AND TRAFFIC *
ARTICLE 4.REGULATION OF VEHICLES AND TRAFFIC *
PART 2. EQUIPMENT

C.R.S. 42-4-227 (2017)

42-4-227. Windows unobstructed - certain materials prohibited - windshield wiper requirements

(1) (a) (I) Except as otherwise provided in this paragraph (a), no person shall operate a motor vehicle registered in Colorado on which any window, except the windshield, is composed of, covered by, or treated with any material or component that presents an opaque, nontransparent, or metallic or mirrored appearance in such a way that it allows less than twenty-seven percent light transmittance. The windshield shall allow at least seventy percent light transmittance.(II) Notwithstanding subparagraph (I) of this paragraph (a), the windows to the rear of the driver, including the rear window, may allow less than twenty-seven percent light transmittance if the front side windows and the windshield on such vehicles allow at least seventy percent light transmittance.(III) A law enforcement vehicle may have its windows, except the windshield, treated in such a manner so as to allow less than twenty-seven percent light transmittance only for the purpose of providing a valid law enforcement service. A law enforcement vehicle with such window treatment shall not be used for any traffic law enforcement operations, including operations concerning any offense in this article. For purposes of this subparagraph (III), "law enforcement vehicle" means a vehicle owned or leased by a state or local law enforcement agency. The treatment of the windshield of a law enforcement vehicle is subject to the limits described in paragraph (b) of this subsection (1).(b) Notwithstanding any provision of paragraph (a) of this subsection (1), nontransparent material may be applied, installed, or affixed to the topmost portion of the windshield subject to the following: ( I ) The bottom edge of the material extends no more than four inches measured from the top of the windshield down;(II) The material is not red or amber in color, nor does it affect perception of primary colors or otherwise distort vision or contain lettering that distorts or obstructs vision;(III) The material does not reflect sunlight or headlight glare into the eyes of occupants of oncoming or preceding vehicles to any greater extent than the windshield without the material.(c) Nothing in this subsection (1) shall be construed to prevent the use of any window which is composed of, covered by, or treated with any material or component in a manner approved by federal statute or regulation if such window was included as a component part of a vehicle at the time of the vehicle manufacture, or the replacement of any such window by such covering which meets such guidelines.(d) No material shall be used on any window in the motor vehicle that presents a metallic or mirrored appearance.(e) Nothing in this subsection (1) shall be construed to deny or prevent the use of certificates or other papers which do not obstruct the view of the driver and which may be required by law to be displayed.(2) The windshield on every motor vehicle shall be equipped with a device for cleaning rain, snow, or other moisture from the windshield, which device shall be so constructed as to be controlled or operated by the driver of the vehicle.(3) (a) Except as provided in paragraph (b) of this subsection (3), any person who violates any provision of this section commits a class B traffic infraction.(b) Any person who installs, covers, or treats a windshield or window so that the windshield or window does not meet the requirements of paragraph (a) of subsection (1) of this section is guilty of a misdemeanor and shall be punished by a fine of not less than five hundred dollars nor more than five thousand dollars.(4) This section shall apply to all motor vehicles; except that subsection (2) of this section shall not apply to low-speed electric vehicles.

When I was preparing to order my kit, I was advised to review the Colorado requirements that "could" be enforced as part of the CSP inspection. Rather than take the chance of failing, I decided to buy the wiper kit and not worry about failing for something that I could mitigate while building the car.

Dave

[Jeff Kleiner]

Thanks Jeff,

Any issues with the measurements in the manual or do you also suggest waiting until the body is on and the windshield is mounted to drill the holes as CDXXVII recommends?

Dave

I prefer to wait until the windshield is installed. Many don't realize that the windshield sits differently on the Mk4 cowl than on earlier cars so there isn't a lot of wiggle room or fudge factor for variations of placement or angle. First very early Mk4 I did several years ago they had not updated the instructions and I nearly cut the holes as per the Mk3 supplement prior to installing the windshield---something told me to hold off and I'm sure glad I did 'cause when I placed the jig with the windshield on it was obvious that things had changed (even if the instructions hadn't ). On every one since then I have waited until it's in place just to be safe.

Cheers,
Jeff

[Papa]

Thank you all for the advice. I'll be waiting to drill the holes until after the body is on and the windshield mounted. No need to rush and end up with the holes in the wrong place. I found a bit and sanding drum to use when the time comes.

Dave

[karlos]

Karlos,

Here is the specific Colorado statute:

C.R.S. 42-4-227


Dave

Thanks Dave; appreciate the pointer. Your approach is the safest one and I should probably be following your lead. But my firewall/dash can only accommodate so much, and I figured I'd get more use out of a heater than wipers. Guess I'll find out soon enough whether or not that statute is actually enforced.

-Karl

[Papa]

Thanks Dave; appreciate the pointer. Your approach is the safest one and I should probably be following your lead. But my firewall/dash can only accommodate so much, and I figured I'd get more use out of a heater than wipers. Guess I'll find out soon enough whether or not that statute is actually enforced.

-Karl

Karl,

I think you may be able to get away with something like this: https://www.amazon.com/Sea-Dog-Remov.../dp/B00DH3UQ9M if you don't want to install permanent wipers.

Dave

[karlos]

Had no idea such a thing existed. Simultaneously the best and the dorkiest thing I've ever seen!

[Yama-Bro]

Can both the heater and wipers be installed at the same time?

[clancypm]

when I drilled them I started with small bits and worked my way up to the 5/8 in bit

[karlos]

Can both the heater and wipers be installed at the same time?

Yes, didn’t mean to imply that they couldn’t. In my case I have a bunch of other stuff also competing for space (glove box, ECU, O2 sensor controllers, fuel pressure regulator, etc). Couldn’t fit it all in there, so the wipers were the odd man out...