Gasket making

I need to make a gasket. It will be about 2 x 3 inches. Pretty simple
stuff. I made one before for my welder carburetor. IIRC, I laid a
piece of paper on it, and rubbed it with dirty fingers until I got a
pattern, then carefully cut it out. It lasted a long time, and would
have lasted longer, but I left it full of gas, and it varnished.
I have cleaned the carb really well, and blown out all the channels and
chased them with pipe cleaners.
I figure to use the piece of white paper again. There are only four
bolt holes, and they have a lot of room for error. I figure this time,
I'll use an X-Acto knife to cut out a lot of the bigger pieces, and a
improvised punch to get the bolt holes.
Any tricks to gasket making? I have enough material to make about four
in case I mess up. Just go slow and easy, I guess. I was going to use
a tiny ball peen to cut off at the outside edges, but decided to leave
about 1/8+" sticking out so I don't have to worry about having too close
tolerances, and having a potential leaking spot. I can just cut outside
the line with scissors, and get it pretty close.
I thought of taking a digital picture, and enlarging it to exact
duplicate scale, and then using that for a template to cut the gasket on
a flat piece of plywood. Might take a little time, but I think I can do
it easily, just include a tape in the pic, and keep adjusting and
printing until it prints dead on.
What would you do?
Steve
Reply to
SteveB
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I'd see how cheaply I could buy the correct gasket first. If I was making a simple carb base gasket I'd measure the hole sizes and centers and lay it out on proper gasket material, then punch out the holes and then mark and cut out the outline. If I didn't have access to the gasket punches I would cut the large hole with an xacto knife
Reply to
clare
I'd start by going to a decent auto parts store and getting some 1/32" thick gasket material.
You'll know it's a decent auto parts store if you say "do you have 1/32" thick gasket material?" and they say "yes".
Reply to
Tim Wescott
Den 19-04-2014 05:00, SteveB skrev:
Is the flange flat? Do you have a scanner and a printer or maybe a copier? If yes to all I simply put the part on the scanner and scan the flange then make a 1:1 print or simply make a photocopy.
Reply to
Uffe Bærentsen
For years people have been laying the gasket material on the part and carefully tapping with a small ball peen hammer to emboss the outline on the gasket material. In some cases like the outside edges you can actually cut the gasket to size with the hammer but in more delicate locations it is usually more practical to cut to the embossed line with a knife of scissors. I usually punch bolt holes with a hole punch.
As I'm sure you know, real gasket material beats everything else for long life and sealing.
Reply to
John B.
Except for the paper, good. I've used cardboard from a cereal box before, but that was because I couldn't find gasket material at my local auto parts stores. Tim has the right idea. DO get the proper material. It comes by the foot (historically) or in several foot rolls (more recently).
I've made them with a ball peen hammer myself, but I've also seen fellow students (Universal Technical Institute, 1972) CRACK and/or dent carb bodies doing that. I recommend against it.
No, better is to measure and cut off a piece gasket material which will be large enough to do the job. Lay that out on the bench, lay the carb body on it, trace around the outside, and cut that line with an exacto or scissors. If there is linkage in the way, guess on the wide side and trim later. Then draw a parallel line around the inside so it is just a bit wider than needed, increasing it to a larger diameter where the screw holes will be. Carefully use the exacto to cut that outline. Now use a hollow punch to cut the screw holes. HF has a set for $6, if you don't already have a set.
No, I think printing would only increase parallax errors.
Once you have a good gasket, make a few more, keep them in a baggie (backed by a little piece of cardboard to keep them from betting bent) and save them with your welder manual. Staple it to one of the sillier warning pages at the front.
Ayup, I heartily second that, Tim. 1/32" at minimum. I used to use long-fiber wheel bearing grease on that material to give it a longer life. They dry out terribly without it. Goop up the cut gasket, let it sit for half an hour to soak in, then carefully wipe off the excess. Gas will eat away any grease within the carb body, but the grease will keep the gasket from sticking to the carb (or, worse, a timing chain cover), so it is easier the next time you rebuild. I'm so VERY glad that automotive technology moved to EFI and I don't have to rebuild carbs any more.
Reply to
Larry Jaques
Another simple method of transferring the pattern is to oil or lighly grease the flange, then press it onto the gasket material. For other castings I've done it with paint too. Light shot of spay fast drying laquer, plop it on the gasket material, press hard and remove. Perfect print.
Reply to
clare
I have laid out the bolt holes, punched them for a tight fit to the bolts; bolt the gasket to the flange and cut the rest from there.
Reply to
wws
Gunner Asch fired this volley in news: snipped-for-privacy@4ax.com:
If you were an old-school mechanic, you'd do it this way.
Coat one surface with Hi-Tack (or a gasket sealer compatible with the job, if Hi-Tack won't work), and stick it down flat on the piece to be gasketed. Hold (press) it flat until the Hi-tack grips and holds.
Finger-press or rub the surface to locate drafts and bolt holes. Just indicate them with slight depressions, don't try to push them through.
Use a tiny ball-peen hammer, like a modeler's size (total head length about 2" and weight about 3-4oz, and LIGHTLY tap on the inside edges of any hole you wish to cut out.
As you tap, the holes will become better defined. If the hole has long straight sides, use the flat end of the hammer for the sides, until you approach the corners, working more and more toward the very tip of the ball as you get into small circles or small-radius corners.
Progressively, you can cut all the way through the gasket material without any damage to the work or the body-portion of the gasket. Fish out pieces that go into holes with and awl or tweezers.
The gasket will be an exact fit, as if it had been die-cut.
LLoyd
Reply to
Lloyd E. Sponenburgh
There is a trick that is rarely needed but sometimes helps.
If your Exacto knife, surgical scalpel or other Very Sharp Blade isn't cutting the gasket material -- gasket paper, cork, whatever -- cleanly, there is a device used by dress makers that may work: a fabric cutter, sort of like an Exacto knife but with a razor-sharp rotating wheel instead of a static blade. Cool device. (Do remember to use it on a surface that won't blunt it in one rev.)
99% of the time, scissors, Exacto knife or Bard-Parker scalpel plus a cheap set of hole (hollow) punches are fine.
Reply to
Mike Spencer
Here'e a related question:
40 years ago I was a foreign car mechanic (back when "foreign car" meant something :-). My recollection is that I used Permatex HiTack, the candy-apple red, aerosol, non-hardening gasket sealer to seal carb gaskets, fuel lines, fuel settling bowl gaskets etc. whenever there was a leakage problem. Worked reliably. And it was *impervious* to gasoline, had to use lacquer thinner to remove it. Any other Old Geezers have the same recollections?
Because more recently, a few years ago, I had to seal a problem settling bowl on a Wisconsin air-cooled. Leaked like a sieve. Experiments showed that gasoline quickly dissolves and cleans off HiTack very well. New can from store, same. New can sent directly from Permatex, same.
Is it new gas additives/composition? Changes in the produst that even the engineer at Permatex didn't know about? My memory has a huge hole in it?
Is there a similar, alternative non-hardening, spray-on gasket sealer that's impervious to gasoline (and diesel, for that matter)?
ObMetalworking: The Wisconsin was intended to drive a 300# air hammer but turned out not to be big enough. A 3-cyl Deutz diesel *is* big enough.
Reply to
Mike Spencer
Yup. Used the spray hi-tack in place of the earlier permatex aviation gasket sealer - which was even nastier to remove.
Ethanol is an effective solvent for both the old permatex and HiTack - and it is quite possible the hi-tack formula has also changed,
The VG4 doesn't make as much power as its size might make you expect!!
Reply to
clare
I would also suspect the gasoline additives. It really wouldn't take much ethanol to soften the compound enough for the petroleum distillates to be able to attack it. Also, the compound may have been reformulated to eliminale chlorinated compounds from the carrier solvent to keep the EPA happy.
I don't bother with spray-on if I can find a suitable thinners to dilute gasket compound from a tube to a brushable consistancy. If Ethanol in the gas is the issue, avoid any compound that recommends any alcohol for cleanup.
Hylomar Blue is reasonably gasolene resistant, though you should use it really sparingly as globs of it squeezed out of the joint are likely to go gooey if continuously immersed and may detach and cause trouble elsewhere. It can be thinned with Acetone and brushed on easily and evenly. When doing engine work, I keep a minature jam jar of it ready diluted, as its best to let it stand a while for an even consistancy.
-- Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED) ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk [at]=@, [dash]=- & [dot]=. *Warning* HTML & >32K emails --> NUL
Reply to
Ian Malcolm
I remember the old amber/red (mercurochrome-looking) stuff which hardened andwas a royal bitch to remove. Lord, I hated that stuff.
Was HiTack the stuff which looked like liquid bluing that had gelled? If so, I remember it. I think it was the very first silicone gasket sealer on the market. Back then, gasket material in half a dozen different textures and thicknesses were available at every auto parts store in town. I always opted for gluing the gasket to the removable part if it was subject to shifting, but never to the engine block, heads, or timing cover if at all possible. Then I'd grease the other side so it left a clean surface and came right off. I remember the glued-on mess left of an aluminum timing cover was stuck to the block with hardening adhesive/sealer. Grr...
Yes, most likely. It's probably being dissolved by the alcohol in the fuel, and maybe even some of the new, highly-toxic additives. None of that was around way-back-when. (And it shouldn't be around today, damnit. I lost over fifteen percent of my gas mileage to the bloody oxygenated fuel we use today. I'm just glad it's E15, not E85. I can't imagine how gutless engines would be on that.)
Pictures, man! Pictures!
Reply to
Larry Jaques
No, hitack was a bright red product - more like a paint.. Not sure if it is still available as a spray, but the msds for the brush-on indicated it is Acetone, Methyl Ester of Rosin, N-Hexane, Rosin, and Acrylonitrile Butadiene polymer
Reply to
clare
The Wisconsin 4 (I forget the model#) is about 24 HP, enough to run the hammer at idle but not under load. The Deutz is ca. 40 HP. The hammer was originally run from a 15HP 400V 3PH motor. I salvaged the motor's shaft to use as a jackshaft between diesel and hammer.
Reply to
Mike Spencer

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