Jan 21 2012

Automotive Spray Painting DIY spray booth

For most people getting into an accident is the worst. In my opinion it depends on the accident. A car accident can be great, as long as nobody was hurt, it’s a small “fender bender”, it’s not your fault, and their insurance is going to pay you.

In my case, for a bumper and taillight replacement, the insurance company was willing to give me $1000.00 This really isn’t worth the work commercially, but since the car was still drive-able, and I’d repair it on my time, I took it. I spend about $300.00 on an aftermarket, pre-primered bumper, taillight, and new paint. I have paint-and-body experience, so the practice was there, I just didn’t have the location.

Ideally, this should be done in a spray booth, but it is possible to do it in a gazebo or carport. The closer one gets to the ideal, the less likely it is to have things land on your paint before it dries. Dust, bugs, water, these are all enemies of your paint job.

What you should have:

  • All walls should be sealed: This can be accomplished with plastic sheeting, and masking tape.
  • There should be a filtered extractor: This can be a square fan, with two basic, blue air filters in front of it, this reduces damage to the environment, as well as over spray for you and your neighbors.
  • There should be a filtered intake: A screen, or metal frame with some air filter material attached to it will do the trick.

That should cover your spray booth if you don’t have a garage. Don’t forget to wet the walls and floor to help with flying particulates, and it doesn’t hurt to wet the air intake filter either. A decent compressor, filter, spray gun, mixing by manufacturer’s specs, patience, practice, and finesse, and you’re on your way to a professional paint job. An actual cross-flow example can be seen here from SprayShield: http://www.sprayshield.com/hazel-doc/BE_CF-1000.jpg


Apr 21 2011

1993 Chevy Blazer Full Size 5.7L V8 knocking lifter

After an accidental redline, while truck was in Park, a lifter became damaged, and my truck starting knocking.  There are limited parts that can cause knocking, and one can usually identify by the location and tone of the knocking, where it is coming from.  While it was easy to identify that if was a lifter, it is difficult to identify which one without disassembling.   Best practice is replace all of them, while you;re already under the intake manifold.

A hydraulic lifer, typically found on gasoline engines, sits in a shallow pool of oil, and is essentially a mini pump.  In the case of a GM 5.7L V8.  The lifter sits atop the camshaft, and due to the camshafts shape, it’s rotation causes the lifters to move up and down at specific intervals as the camshaft rotates.

Right over the lifter sits the push rod which serves two functions.  It pushed the rocker arm, and also allows the lifter to pump oil into the upper valve heads.  The lifter has a piston inside, and spring, as well as a hold on the bottom end, and a hole on the top end:

 

 

 

 

 

The push rod is hollow and allows oil to squirt up through it.  In essence:

The camshaft pushes the lifter up
The lifter pushes the push rod up, while sending a oil through the rod
The rod pushes one side of the rocker arm up as well as dispersing oil
The rocker arm pivots and pushes down on the valve which allows fuel in or exhaust out depending on the valve.

Here’s a short on what my engine sounded like with a failed lifter:

 

 

So after hearing the noise, I was all like, “time to identify where it’s coming from”.  The best tool for this is the stethoscope:

 

By the sound being louder when checking the engine block, versus anything else moving around the engine, one can infer that the problem is within the engine block.   Eliminating any issues caused by the pulleys, belts, or anything being rotated by the engine crank.  The next step is to figure out if the noise if closer to the top or bottom of the engine, this can be done by listening to the engine block, then valve covers, then oil pan.

In this instance, the location and frequency of the sound, identified the problem as one of the lifters.  Usually the lifter’s spring will fail, or the bottom will fail, creating enough slack that camshaft “knocks” the lifter into the push rod.

 

The lifters on the 5.7L are located beneath the intake manifold.  So the valve covers, intake manifold, distributor, and heads must be removed to access the lifters.  This is a good time to check for other problems and refurbish the heads.  This is basically known as an upper engine rebuild.  The engine does not have to be removed.  I didn’t do it, but I probably should have.  Here are some pics for reference.    Please note that for the distributor pic the engine is in TDC (top dead center).  This means that the number 1 piston is all the way up and in firing position.  Also, when removing the distributor, it is normal to see it rotate a good 45 degrees counterclockwise on it’s way up.  The same must be reversed when it is installed.  This is due to the fact that the gear at the end of the distributor is a helical gear.


Feb 23 2011

Solid-State Hard from USB Flash Drive

The hard-drive controller on the motherboard for this laptop went bad.  Instead of throwing it away, I decided to turn it into a Solid-State enabled laptop, for less.  My intention was to make a picture frame out of it.  I gave up on the picture frame once I got the OS and everything working.  I didn’t have the miter saw to make the frame at the time.  But here are some pics of the USB Cruzer as the boot up drive. Enjoy!


Jan 26 2011

Bi-folding metal gates design and build

As most projects and experiments do, this one began with a problem. I was determined to have to driveways in front of my house, but didn’t have the room for the gates.

Designs:
Swinging…
Installing swinging gates was not an option. Swinging gates would require the vehicles to park far in enough so that they would have to clear the vehicle for then to close.

Rolling…
I got a few estimates and ot suggestions from fence contractors and they settled on what they knew best, rolling gates. Unfortunately, it looked great on paper, but when I actually measured it out, the criss-crossing gates were not going to look good with the cement columns.  One of the gates would have been about 3 ft from the sidewark.

So I figured, “OK, I’ll have to design them myself”.  And, inspired by the wooden closed bi-fold design, the mission began.  I originally had no intention to design them on the computer.  Once I realized that the wheel was not going to be mounted at the tip of the gate, and I had to make each half of the bifold a different size, I decided to draw it.  It’s easier to deal with mistakes on CAD than after welding, so I put some WD-40 on my Into to Solidworks skills, and went at it.  Once I started, I was hooked.  And this was the final product.


When I started to weld, I realized that I didn’t have a flat surface to weld on, and could make a perfect cube structure this way, so I designed a jig…

I poured and installed the tracks first, and built the gate to the tracks.  It took a lot of tweaking, but in the end they look great. 

…and after the driveways.

Once I can afford 4 swing motors (or until another ENG course teaches me how to make them), I’ll complete the set up.


May 5 2010

Flexible Vinyl Paint

http://www.flxpaint.com/

This is pretty much like plastic painted with car paint.  Kind of like vinyl but not at all.  It actually has a clear coat on it that can be wet sanded, buffed, etc.  As far as production, it’s cheaper to paint cars, but for aftermarket paint jobs, this is the future.

In order for those of us who are shopless to paint a car, we need a makeshift booth or spend $150 to rent one at a shop.  Yes it will take approximately two cars to come out half bad in order to learn this (just like base coat / clear coat) or Awl-Grip for that matter.  But once the skill is obtained, a car can be prepped at home and then this material applied.  Also, there’s no issue with moisture, baking of the paint, etc.  It will have some growing pains, but with the popularity of car wraps right now, I see this taking off.