Posts: 77
Joined: 2/12/2007 From: Riverside,
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Hey all. I needed to replace the case gaskets on my OS Max 40 FSR and found out after searching Tower and Omni that replacement gaskets aren’t available. Next, I searched the RCU Glow Forums and found some great suggestions on making gaskets for our engines, but no pictures of the process. So, I decided to make a set of gaskets and post pics of the process I used. Only took ten minutes to make them. There are a lot of great suggestions on making gaskets here in the RCU Forums, but nothing consolidated into one location.
I decided to post here in the tip and techniques forum as this seems the most appropriate place to do so.
Note I didn’t find out until after I made the gaskets that the OS Max 46LA uses the same size as my 40 FSR (need verification on this).
First I cleaned the surfaces of the of the engine that need the gaskets. Next I grabbed the closest piece of paper that I could find, a used piece of printer paper, and cut out an oversize square of paper, about 2” x 2” to use as my new gasket.
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Joined: 2/12/2007 From: Riverside,
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Using a cheap tinning brush I lightly coated one side of the paper with some contact cement. I did the same to the case gasket surface, trying to avoid getting excess cement inside the case. Write away, using a flat as surface I could find, I pressed the crankcase down onto the paper I coated with the contact cement. This was to make sure any excess contact cement squished out to make a nice flat adhesion surface.
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Joined: 2/12/2007 From: Riverside,
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I waited a few minutes for the contact cement to dry. I then got a sharp x-acto knife and started to cut the on the inside, but decided it would be better to shave the paper off around the outside of the engine first to keep tension across the inside of the new paper gasket. I continued around the case using down strokes to cut the paper off to avoid lifting the new gasket material off. No upstrokes. I’ve tried several other methods to cut out the gaskets in the past, from scanning the case and printing it back out and then cut or using a drafting pencil to tracing the case onto paper then cut. But I find that using the contact cement makes this method really easy as the paper stays put.
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Joined: 2/12/2007 From: Riverside,
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I trimmed up the inside and then started on the bolt holes using the same method as before only smaller down strokes until the very last cut, at this point fold out the remaining paper so it doesn’t drop into the bolt hole and finish cutting it off.
< Message edited by Roguedog -- 5/17/2008 3:25:02 AM >
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Joined: 2/4/2006 From: Dorr, MI, USA Status: offline
I did something along those lines for a case gasket for an HP .61 Gold Cup. I cur it out of brown bag paper, coated it with light machine oil, and ran it (worked flawlessly).
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Another cheap, readily available gasket material is to use an old playing card. Your local auto parts store sells rolls of gasket material for heavier use gaskets, such as as engine block to tuned pipe header joints.
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Joined: 2/12/2007 From: Riverside,
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quote:
ORIGINAL: jetpack
"Perfect" brand gasket material is still being offered by the company. Its nice and thin and made for our engines.
Great tutorial, Rougedog. Nice to see a thread on it.
Thanks jetpack for the tip on the gasket material. I went to Tower Hobbies looking for the OS 40 Gasket kit, which is not available. I never thought to look in see if they carried thin gasket material for making your own. Tower Hobbies carries the "Perfect" brand of gasket material you mentioned.
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Joined: 4/21/2003 From: Hemderson,
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I used to make my own using coffee machine filters. I would coat the paper with red high temp silicone then stick the paper between two sheets of glass and put 25 to 50 pounds of lead shot on top. I covered both sides of the paper. Today I haven't run into any problems finding gasket sets for my engines, I keep them in stock so I always have them. I do have A bunch of very old engines though and I like how you used the glue so you got that perfect fit. I think I will give that A try when I open these old engines up for there cleaning. Thanks for the idea.
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Gray Beard mentioned RTV. I stumbled on something while re-doing the brakes on my car and now I'm using it on my engines.
It's called "Brake Disc Quiet" made by CRC. It is latex instead of silicon, and is a flourescent red color. It has no nasty amonia smell and cleans up with water before it sets up.
It is great for places without a gasket that need sealing, sets up pretty fast, and is easy to remove when its time to come apart. I find the advantage of how it works is it shrinks down quite a bit, but still keeps its seal. Anything that squeezes out can be wiped off with just a water-damped paper towel or finger.
It is a lot cleaner to mess with than RTV, and although I haven't tried it yet around the exhaust, it should be high temp because of where it's used on disc brake pads.
Another advantage is it is transferable to any small squeeze bottle. I found one for crafts that has a very fine tip and I can draw out a very narrow tall bead of it. Great for backplates and such, and think it would work well with Gray Beard's idea too.
All my clunky messy RTV tubes are off to the side now, and having it on the shelf for over a year shows me it doesn't cure in the bottle like an RTV tube would.
I got mine at the auto parts store. I noticed they even sell ketchup packs of it if you just want to try it out before buying the bottle. I guess a small paintbrush would work with that. It does skin over pretty quick, so work fast if you use one.
< Message edited by jetpack -- 7/4/2008 5:47:49 PM >
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How to make case gaskets. - 
