Wednesday, October 10, 2018

Motorcycle Tank Rust Removal with Evapo-Rust


You can see a thin layer of red rust on most of the inside.


Much better! Almost all of the rust is gone. You can see some pinkish paint overspray on the inside of the tank, don't confuse that for rust. Whoever painted this tank must not have masked off the filler opening. The red oil in the bottom of the photo is some Marvel Mystery Oil I used to prevent rust.

What I used

I found this stuff called Evapo-Rust that had good reviews. I had used it on a couple items and was very happy with the results so I decided to try and use it on the inside of my Mondial gas tank.

The manufacturer of Evapo-Rust claims it is relatively safe. This is from their website:
"Evapo-Rust® rust remover is safe on skin and all materials except rust! It's also biodegradable and earth-friendly. Water soluble and pH-neutral, Evapo-Rust® is non-toxic, non-corrosive, non-flammable, and contains no acids, bases, or solvents. Evapo-Rust® is simply the safest rust remover."
They also claim is is safe on paint:
Powder coating and paint will not be removed as long as the paints do not contain oxides.
However, NOTE the exception they mention about oxides! Some paints do contain oxides, particularly red paints. Use care, especially around red paint.
I also saw it damage the clear coat on some of my decals. I was able to clean this up on my tank without trouble, but you should be careful!

My Mondial gas tank is 16 Liters or 4.2 Gallons.  Conveniently, the Evaop-Rust is available on Amazon in various sizes:
Evapo-Rust 1 Gallon

Evapo-Rust 5 Gallon Pail

Other items I used:
90% Isopropyl Alcohol to help rinse out the tank.

Marvel Mystery Oil to coat the tank after cleaning to prevent rust.

How I did it

I took the tank off the bike and removed the petcocks. I've heard people have done this with the petcocks installed but I didn't see any advantage to trying that. I made two petcock hole plugs out of a pair of bolts that I shortened and some rubber washers. I also used some teflon tape to help seal the plugs.

I put some plastic down and used a aluminum turkey roasting pan to catch any drips. I also put some blocks under the tank to hold it off the bottom of the pan. I made sure the top filler of the tank was perfectly level so I could fill the tank completely.

After filling the tank, I made sure the outside of the tanks was completely clean and that the was no evapo-rust on the outside. I didn't want any chance of damaging the paint!

And then I left the tank for a couple hours. I'm not sure exactly how long, but it was more than 2 hours and less than 4.

I've seen metal "flash rust" quickly after de-rusting, so I really focused on completing the next steps quickly.

When I decided the tank was "done", I emptied the tank into a large plastic bin so I could recover the Evapo-Rust for future use. And the I immediately washed the outside and inside of the tank with water. (It was really nice that the Evaporust is biodegradable, minor spills were no concern!) 

After shaking the tank out I put in about a cup of 90% rubbing alcohol and shook it all around and then drained that. And then I repeated that again with another cup of alcohol. The idea is the alcohol blends with any remaining water and then dries out quickly. 

But I was still concerned about flash rust, so after shaking out all the alcohol I could I immediately poured in about half a cup of Marvel Mystery Oil and shook and tilted the tank every possible way to coat the entire inside. I poured out the oil and repeated this step again with fresh oil. After the second oil coat the excess oil poured out looking nicely unpolluted with water or alcohol.
(Note: I wouldn't count on Marvel Mystery Oil for long term rust proof storage of an empty tank. But for short term use before filling with gas it is good. Marvel Mystery Oil is commonly used as a fuel additive and it a pleasing peppermint smell.)


I think the tank came out very well. Most of the tank looks great. That might be a bit of rust left in the bottom, I probably should have left it a bit longer or maybe rinsed it once and refilled for a second Evapo-Rust treatment.

I'll be curious how long this lasts. Some say they you should use a treatment that leaves a coating to protect the tank from rust, they tend to recommend a phosphoric prep and etch. I have done that in the past, but dealing with the acid is very hazardous! This Evapo-rust is much easier. As I said, we will see how it lasts!

Friday, October 5, 2018

Pi-hole advertising blocking and DNS - a complete kit

I decided to build a Pi-hole to block advertisements from our home network and so I could use it as a separate DNS server from our router. I set mine up on a Raspberry Pi 3 B+ that sits headless (without monitor, keyboard or mouse) next to my router.

Detail on technology: Pi-hole and more mmm-pi-hole.
Detail on the Raspberry Pi Hardware: Raspberry Pi.

As I built this thing I discovered a few things so I thought I'd share some tips. These are not detailed directions, just a basic outline of what worked best for me. If you know your way around this kind of stuff (setting up DNS servers and home routers) it will probably be enough, but if you don't, consider finding a more detailed guide than this one! 

Here is the hardware I chose (with pricing today 2018-10-5):

Raspberry Pi 3 B+ Motherboard $40
Power Supply with switched cord $10
32GB MicroSD card and adapter $9
Flirc Aluminum case with integral heat sink $16

Total cost: $75
(You will also need a monitor with HDMI cable and a USB keyboard and mouse.)


  1. First you need to format the SD card as FAT32.
  2. Next you need to install an operating system image on the SD Card. Raspian (Debian for the Raspberry Pi) is the obvious choice. Most of the directions recommended using "NOOBS", an installer program, but I found it set up a corrupt image on my card, and googling showed many people had problems with this. I tried the alternative method and actually found it to be much easier and I highly recommend it:
    1. Download Etcher (the image flasher)
    2. Download Raspian Stretch with Desktop (the OS)
    3. Unzip the Raspian Image
    4. User Etcher to Flash Raspian onto your SD card.
  3. Put the SD card in the Pi motherboard and connect the monitor, keyboard and mouse. Power it up!
  4. Once you have configured Raspian, you need to install the Pi-Hole software. Follow the directions on the Pi-hole website, its easy.
  5. Note, if you configure the Pi-hole initially for wifi, wlan0, it will not work over a wired Ethernet connection! You will have to go back and change the connection to your wired Ethernet port, eth0 or to "all interfaces".
  6. Configure the Pi-hole DNS as you desire. Be sure to note the password! You will need to assign it a static address on your network (see your router configuration for that) and point it at the appropriate upstream DNS servers of your choice. If you stream video services, I recommend using the servers assigned by your ISP or some other quality local server. Good article on CDNs and DNS.
  7. After power cycles, Raspian and the Pi-hole application seem to boot automatically. So you won't have to login or start the Pi-hole application manually after every reboot.
  8. If you want to operate the Pi without an attached keyboard or monitor, you can enable the VNC server built into Raspian. You can find this in the "Raspberry Pi Configuration Menu" under "Interfaces". You will need to install the VNC client on whatever device you want to use to view the server. Hard core users can enable SSH if they wish.
  9. Note you can access the Pi-hole software from any device on the local network by entering it's address in your web browser.
  10. At this point I tested the Pi-hole by telling a single computer to use it for DNS. When I was happy with how that worked I then changed the DHCP DNS settings in my router to enable the Pi-hole for the entire network.
  11. It works great!
I will note; there is not much visible improvement on a computer for the end user over something like uBlock Origin. However, the Pi-hole works great for smart phone and tablet users! And while it doesn't appear much different to computer users, it does substantially cut back on network DNS requests. The results are visible in the picture at the top of the page.

Saturday, July 14, 2018

Dad's APH-5 Flight Helmet

Spent some time restoring Dad's APH-5 old flight helmet today. The helmet is from around 1957. In the early 70's Dad had stripped the helmet of the headphones and microphone for use with his ham radio. And then the visor was broken and the knob to retain it lost, probably due to my playing with it as a kid!

I was able to source original replacement parts on eBay and from a helpful person on the forum at I disassembled the helmet cleaned it slightly and then carefully soldered some wires and fitted the pieces back together. It will be a great display piece!

More pictures:

And here is a funny card Dad received during his helicopter training. It appears they handed these out after the student mastered hovering and some other maneuvers.

Even the back is a little strange! This must have had some strange meaning to the pilots...

Monday, June 18, 2018

Bosch GLL 100 Green-Beam vs Bosch GLL 2-15 Comparison Test and Review

Bosch GLL-100 vs Bosch GLL 2-15 outdoors on an overcast day in the buildings shadow.
These lasers were set up 7 feet from the wall.
The arrows point to the crossing point of the respective beams.

My trusty Bosch laser level is a great thing but it just doesn't work in daylight. I'm always waiting for dusk to use it on outdoor projects. I've heard these new green lasers are better, and the manufacturers advertise them as 4x brighter. So I decided to get one and try it.

Outcome: The new Bosch GLL-100 is not much better than my old GLL 2-15. And it is much larger. I will not be keeping it. Note the attached photo, taken on an overcast day in the building's shadow. The green laser is just barely visible, a bit better than the red laser. But still not usable outside. If you are using this indoors and do not mind the size and price, or just need a new unit, it is great. But I wouldn't recommend it as an "upgrade".

Wednesday, April 18, 2018

A Garage Attic Design

I've seen a couple posts about garage attics lately and that prompted me to document mine a little better. Having done it, frankly, I think it is a mistake to build any garage that has a good pitched roof without an attic (unless you are doing a cathedral type ceiling for your car lift or something).

We moved from a larger home to a much smaller one in the city, and the new home is a 1926 Craftsman, with very limited closet space. We knew we were going to build a garage and a very usable attic became a priority. I'm mostly a motorcycle guy so the garage didn't need high ceilings for a lift and I kept 8' ceilings in there. But the city also limits the heights of garages to 15' so my attic space was destined to be cramped.

I decided it was very important to have a great garage stairway, and I documented that a while back here:

I found getting the trusses I wanted a bit of an exercise. The truss company was run by a fairly ornery codger and communicating with him was tough. He was happy to design the trusses for free as part of the truss order, but I wasn't sure he was really optimizing the truss to my needs. But I found he had the trusses stamped by an outside engineer, and I just contacted that guy and he was very happy to help.

Given that I wanted to maximize my headroom, we used a triangle at the apex of the truss, instead of the typical cross piece that would have reduced headroom.

Also, my trusses are "strangely" spaced, as I wanted a larger gap for a wider stairway, and the building itself wasn't designed in an increment of 2' for the trusses to be evenly spaced.

My design was checked for 200# per truss for the stairs, plus 40 PSF total load in the 9’ wide attic area. Note also that my truss is worse case design at 28.5” on-center, with the trusses at 1’-4” and 2’ on center not carrying as much load.
The wide spacing was to accommodate the stairway, and that is only in one spot. Most of the trusses are on 24" centers, so that effectively makes things more robust than the calcs show.

These are still pretty basic trusses made of 2x6, 21' long, 6/12 pitch. 13 trusses (9 attic plus 2 end trusses) cost me $1870, delivered, here in expensive San Diego.

Here the attic truss design. Note the triangle at the peak, and the maximized attic area. It's not quite tall enough for a short person like me to stand it, but you can move around up there.

Here are the end trusses. A wider space open in the center is for the attic fan on one end. On the other end we have a fancy vent, so the verticals were spaced to match that design.

Here are two shots during construction.

And on this shot shows the fan end vent from the inside. Also note the 3/4" plywood floor.

A garage attic. I highly recommend it.

Saturday, March 3, 2018

San Diego Historical Homes: How to get the "Mills Act" Historical Designation

We live in a pretty little home that has received the "Historical Designation" here in San Diego.
When we were house shopping, we had hoped to find a home that either was eligible for the historic designation or already had it. I did do a lot of research on the matter and wanted to document some of that here.

People often ask me how to get the designation. In short, you hire a professional who researches your home and it's eligibility and they handle the application with the city. There are a couple architects and other firms that do this here and if you google I am sure you can find them

But the city also provides a lot of background information about how to apply. You can learn all about it here:
San Diego Historic Preservation FAQ

I often recommend  that if your house seems "very eligible", consider doing the research and making the application yourself. Now, I have never done this, but it seems worth considering! And no matter what happens, you might learn some things about your home.

 Here are some tips that are not spelled out in the FAQ above:

Was your home built by a Master Builder?
The city keeps a list of "Master Builders". These are recognized builders and if one of them built your home it is a good start to being found "historical":
Biographies of Established Master Builders

If your house was built by one of these "Masters" and another home very similar to your home has been approved, you may be able to use much of the information from the approved home's application.

Has your home been surveyed already?
There are also old surveys of the homes in the city, like this one of North Park, that list homes that may be of historic interest:
2004 North Park Historical Survey
That survey lists most of the homes in North Park, and hints at whether the homes are "contributing or "non-contributing".

You can also check the 2011 North Park Historical Survey

And there are lots of other surveys here:
San Diego Historic Contexts and Surveys

Is your home just like one that already has been approved?
And here is the actual list of homes already approved:
San Diego Historical Register as of 2014
(There may be more recent versions of this available)

How to find the "Full Nominations" (Applications) and "Final Resolutions" for homes that have already received the Historic Designation?
If you find that your home is just like another home that has already been "designated" you can look up the the application.
Here is the California Historical Resources Inventory Database

Here is a home I have randomly picked from the database above:
Look at the wealth of information available! I'd suspect that if your house looked just like that and was built by the same builder you could likely use most of that application to write your own application for your home.
You can also see what professional firms have done successful applications by looking at the applications for the homes already designated. If I was hiring a firm to do this for me, I'd use one of those.

Have fun researching your home! And always consider hiring a professional to do the application, it is probably a lot easier.

PS: On what structures to include in your application:
Be careful what you include in your application for the "Historical Designation". You can choose what buildings and other features are included in the application and you may choose to leave out items. For instance, you may wish to apply for your house, all the hardscape (walkway, driveway) and the separate garage. But after the designation, then you may not be able to change your walkway, or make your garage into a residential unit! So you may wish to only apply for the main residential structure.

Sunday, November 12, 2017

Is your concrete flat?

How to get a flat concrete garage floor? I posted the information below on a forum when I was researching how to specify a flat garage floor and what standard of work could be expected:

What does flat mean? First of all, flat does NOT mean level.

Flat: smooth and even; without marked lumps or indentations. No concave of convex areas. A vertical wall, sloped surface or level floor can be flat (a flat surface can be sloped).

Level: a perfectly horizontal plane with respect to the distance above the center of the earth. A bubble level will show this to be level in all directions

On the high end of concrete floors, you can have "super flat" concrete installed, they do this particularly for warehouses that have high lifts and robots that run in the isles. However, this requires laser guided machines than smooth and flatten the concrete. I don't think many of us are going to do this for our relatively small backyard garages or shops.

There are some standards for flatness and levelness and these are measured in FF (flatness) and FL (levelness) numbers. And these are not easy things to measure. The sell special gizmos to do the measuring. Essentially, measuring with a long straight edge isn't really acceptable, because each person who measures will measure differently. The other obvious problem with using a straightedge is that what you really want to do is hold that edge just above the plane of the floor and then measure below it, you don't want to just lay it on the floor. Companies make cool gizmos to actually measure FF and FL, and they are pretty sophisticated (see

I called a bunch of concrete guys. Essentially, none were willing to commit to a standard like "less than an 1/8" dip below 6' straight edge anywhere on the floor". After my floor was poured and I wanted to make it flatter, I also spoke to a couple grinding and polishing companies that sounded interested in "flattening my floor and they said "oh we can definitely make it flat", but as soon as I mentioned my 6 foot straight edge they lost interest. No one had a plan or a method to make the floor flat. No one said anything about flooding the slab and marking high spots, or anything like that. No one owned an electronic dipstick to measure flatness. I suspect this stuff just doesn't happen in standard residential construction.

I did find one company that seemed pretty competent at flattening concrete floors and their info mentioned they do "slab correction". This guy does lots of work including warehouses that use high lifts that really need flat floors. Essentially, he said my floor was "normal" for work these days (sadly). He could make it better and wasn't wildly expensive, he'd charge just somewhat more than a regular floor polishing for the extra time and effort. But he questioned making an effort to get it really within 1/8".

I found this chart online:
"Although there are no direct equivalents between F-numbers and straightedge tolerances, ACI 302, "Construction of Concrete Floors and Slabs," gives the following table of approximate values:

F-number Gap under an unleveled 10-foot straightedge
(fraction of an inch)
FF12 1/2
FF20 5/16
FF25 1/4
FF32 3/16
FF50 1/8

Apparently typical concrete floors are in the FF20 to FF25 range. I did find this statement: "Although "1/8th inch in ten feet" has been used to specify billions of square feet of concrete, it was seldom, if ever, achieved. The typical industrial floor, for example, is closer to a 5/8th inch deep envelope, rather than a 1/8th inch deep envelope."

A big issue is that typical concrete guys never check their work. How many visit the site 30 days after the pour and measure the surface with a proper dipstick style gauge according to the standard? So essentially, your residential concrete guys do not really know how good or bad their work comes out!

I'm a geek, so when my concrete cured enough to walk on, I went out and tried a 6' straight edge all around the floor in a grid pattern. I really tried about 40 placements. Only one area was out of whack. Mine may not be that great, but I also suspect very few people have garages that would really meet the FF50 (1/8") standard.

On contracts. I've been around the track a couple times and I understand these things. It sounds great to have everything specified in a contract and to have it be enforceable. In my case, I didn't know enough to ask the details about flatness, let alone specify something. But at least around here, it wouldn't be easy to even find a residential contractor with a dipstick gauge who would commit to an FF number. The other problem is that the residential finisher is usually a subcontractor who makes a modest wage. Even the head contractor , unless he is a big outfit, isn't in a financial position to "replace your foundation" if it doesn't work out. Certainly, the finisher, who is maybe making $250 to $1000 is going to disappear before buying you a new slab. I personally think you are just far better off trying to understand what you can get, checking references, and looking at similar work than expecting the contract to make it "all right". In my case, yes, I wish the floor was better in one spot, but I can live with it and I'm not going to make others pay for something I didn't understand well enough to demand better.

So, in conclusion:
I'm no expert on concrete, but having done this once, and read some others advice; here are my recommendations:
- You aren't going to get a "perfectly flat" floor, especially with high PSI concrete poured on a warm dry day.
- It seems harder to make a floor with a curb (stem wall) around the edge flat (especially with just one pour) than a slab without a curb, as the finisher cannot use the top of the form as a guide when there is a curb. If you are going to have a curb/stem wall, perhaps look into doing the floor as a separate pour.
- Talk with the actual finisher, not only your general contractor, about what he can do. Make sure he knows this is going to be your "pride and joy", not just another lousy garage. Make sure he has a wide bull float and will run it both ways, North-South and East-West. Is there enough room to run the float both ways or are other buildings in the way? Go see similar work he has done and if it matters bring a dipstick or at least a straight edge. Does he own a dipstick? Has he ever returned to a job after it has cured and tested the floor's flatness?
- During the job, have him show you it is flat, while it is wet. Maybe they can go out with skis and show you a straight edge on the surface.
- Don't let any of the finishers hang out on their skis on the floor. If they stay in one spot too long they will make a depression. (My low spot just happens to be were a finisher hung out playing with his phone while he waited for the concrete to get a bit dryer.)
- Lastly, If you can get it close to a 1/8" gap under a 10 foot straight edge, you are doing amazingly well. 1/4" is probably more reasonable.
- Be present during the pour and finishing, ask questions, and make them do it right.

PS: On sloping the garage floor vs making it level: 
Most people slope the garage floor so liquids will drain toward the car door opening. This can be particularly important in places where it snows or rains significantly, and it maybe part of the building code.
Often, concrete finishers who slope the concrete significantly care much less about flatness. The more the floor slopes, the less likely water will puddle! Typically, builders who slope floors do at least 1/8 inch per foot (1 inch in 8 feet). If the floor is sloped sloped significantly, many people will want to level things like workbenches, shelves, and floor mounted tools with leveling feet. And if you must have leveling feet for the sloped floor anyway, flatness may not matter as much to you.
But be careful with floor slope; some builders will slope the floor as much as 1/4 inch per foot or more. That would be 1 inch of slope in 4 feet. It's also 4 inches in in 16 feet. Many would consider that too steep for many garage uses.