Intro: Gasket Making Using Laser
One day I was faced with the task of rebuilding one of my engines. After a lot of cleaning and dismantling I realized I have to invest and install new gaskets all around. I found out that they were expensive and in some cases impossible to get any more... yet I still bought some over the internet (the local dealer buys them from the same people) and after a lenghtly wait they arrived.
They were rather sad excuses, expensive, poorly made garbage, and in two cases they arrived broken in two !?!?!!!
So, I set to make my own. First I wanted to make some CNC stamping dies but the local TechShop just opened up and I was able to use the lasers here. A much cheaper and faster way of making gaskets.
Locating proper gasket material was a chore in itself, finally being able to get proper material from a local Grainger. They sell different thicknesses and it is not rolled, but flat, protected between sturdy cardboard sheets. I had to cut the original down to fit the 24x18 lasers here, but that was easy using a shear. The left over piece was big enough to get some more out of.
All these type of gaskets use fibrous material, good seal to petroleum based liquids and rater high temperatures and are used throughout most engines except for the exhaust. They are organic not azbestos.
They are LASER sharp !!!
I have been using my car, for two months now, with these installed on and I have no problems!!!
I made it at TechShop Chandler, techshop.ws.
Step 1: Gather Materials
Obviously you need some gasket material. In the old days gaskets were made out of waxed paper, oiled paper, cardboard, leather, sometimes a soft metal (copper, aluminum) nowadays gaskets are made of more high tech stuff or a mixture of layered materials. Try to figure out what the originals were. Usually they look like some colored or gray cardboard like stuff which is mixture of fibers and binders. It is nothing fancy, just gasket material. Get the thickness. I have found that 1/32 is rather common on all cars and motorcycles. Sometimes the next size down for more delicate components, but if you put the same stuff all around it should be OK. Sometimes they are put on dry, something with a sealant (RTV is Common). It is best that you try to get the manual and see what they say about it...
When you buy the stuff it also has some specs on the webpage, it is good to 3000PSI so unless you build a space shuttle your car of moped should be OK with them.
I used gasket material from Grainger (the green stuff in pictures), some cereal box like cardboard, or thin matboard (overkill) and some heavy 110lb sheets of paper. Get a fine marker also it helps making notes on the gaskets as you adjust the sizing later. After making several hundreds I was getting confused....
Step 2: Draw Your Gaskets
The easiest way is to copy or trace an existing gasket. That is not always the best way. I have some brand new gaskets that were rather shabby and off, in sizing, partly because the traditional method, is stamping them in thick stacks with a cutting die. If your gasket is from the lower part of the stack it is deformed and crushed...
See my other tutorial on centering pins, to establish correct geometry for complex shapes. I use a drawing program, such as Inventor, Solidworks, Corell or Illustrator to get my gaskets drawn to my liking.
I usually saved them as PDF files so I can maneuver and view them easily. The lasers here at Techshop Chandler use Illustrator to do the cutting, so I work from there. For settings I experimented a bit to get the right power, but in the end I used the settings for leather, being an ntural fibrous matter also.
It turned out that for 1/32 gasket material leather thickness of twice that will actually cut properly. This green stuff is tough...Some fine attachments are still left, but that worked out to my advantage as I cut a whole 24x18 sheet at a time and wanted to take it all off the laser still attached and pop out only what I wanted for the time being. The rest I stored flat in the cardboard covers that the gasket material came in, originally.
Step 3: Do Some Test Cuts
Although I am pretty good with calipers, some of the gaskets were not quite "spot on", however I anticipated this, and I did my drawings in such a way that I can change some dimensions without altering the whole gasket so I can inch my drawing to the right spot in relationship to the holes and overall shape.
I cut first proofs in 110 Lb thick paper and lay them over the parts to check the fit. The paper is rather stiff and allows for handling. I also made notes right on them, so over the several revisions I did not get confused. Use "construction paper" settings for the laser, and for material thickness measure with calipers and input whatever paper thickness you end up with. Each gasket was done on a separate file so I can cut them later individually if I so choose.
Step 4: Final Setup
When I was happy with the shapes obtained, I created one big sheet 24x18 in Illustrator, and cut and paste one of each of my gaskets on to it. For me some gaskets needed to be 25.5 inches long so I laid them out at an angle because the laser table is only 24 inches wide. I took my time and nested all gaskets as close as possible, also making use of the free space in some of the openings where I nested some more of the smaller gaskets. I think I managed to use maybe 90% of the surface.
Using some scrap cardboard about as thick as cereal box stuff I cut a piece that was 24x18 and laid it on the laser bed and cut it away.
It turned out that, for a large sheet that was wise as the laser and bed had some alignment issues to sort out and I did not wasted my $36 a sheet worth of actual gasket material.
This way I actually noticed that I could pack the gaskets even better and squeeze 4-5 more in (small ones). The actual cut spaces in the cardboard mock give a better perspective than the computer screen, also the spacing between could be adjusted better judging by the laser cut lines.
Do not overlap gaskets thinking you can cut two gaskets that share a common line. Unless drawn like that on purpose, the machine will go over the same line twice resulting in a less crisp cut line.
Step 5: Cut Some Real Gaskets!!!
Well we are at the end, lay down your real material, it is worth taping it down, if it is thin. The 1/32 is rather dense and lays down pretty good. It feels like Linoleum because it is dense and somewhat pliable. Try not to bend it, it will crack, and that is no good...
Set your machine for the right thickness (of course you did some testing, right?) and hit GO.
A whole sheet cut, for me in about 18 minutes. There was little smoke and no flares. The gaskets had some fine grit on them from the laser cutting but it was easily wiped with a moist paper towel.
I preferred that my sheet stays together more or less, so it is easier to store in the original gasket packaging. Later I just popped out what I needed and left the big sheet intact.
It is a good idea to etch some identification part numbers on them to sort them out easier. Set raster to low power so you just barely make a readable mark, you do not want them too deeply scribbled on...
Cost wise, I saved a bundle because a complete gasket engine kit like mine was around $120. On a 24x18 I got two complete sets and maybe another dozen of the small gaskets from a third kit. That is pretty good for under $40... Of course it took some tinkering, but now I can chug along hundreds in one hour. I only have 5 of these engines though, but hey,
I hope somebody reads this and they get some useful info out of my hard work