Author Topic: "lint" in fuel filters (Read 3368 times)

Skip Chernoff · « **on:** August 07, 2018, 06:14:05 PM »

I've been making my own fuel for decades,but recently I've been plagued with bad engine runs caused by what looks like "lint" in the screens of my fuel filters. I use VP M1 methanol which I've been told is the good stuff. Anyway I need to filter my fuel before placing it into use. My question is.....have you guys experienced the same thing ,and what type of filter is best for separating the lint out?......Thanks,Skip

Dave Harmon · « **Reply #1 on:** August 07, 2018, 06:29:55 PM »

Yep....same here.
I also mix my own stuff and I've found over the years that the 'lint' is usually in the castor oil.
My guess is that you are using some castor...right?
Whenever I pour methanol I always strain it through a coffee filter.
Can't strain the oil or mixed fuel this way as the oil is too thick to pass through the filter.
In addition....avoid the use of paper towels when cleaning out the pouring container....but I cheat...I use paper towels but always swish out the container with methanol immediately after then put the container upside down until ready to use.
These days....I don't have any more lint that I can detect and the filters are always clean....but....I regularly back flush them anyway.

If you have castor or other oil with lint you can mix the correct amount of oil and some methanol in another container, then use the coffee filter in your regular jug and pour it through. This will thin the oil enough so it will go through the filter....might take a bit longer but it's better than having lint in the fuel.

Brent Williams · « **Reply #2 on:** August 07, 2018, 06:36:25 PM »

The "lint" is caused by the extrusion of castor oil through the fine mesh filter screens. It causes the fibers to be made over time.
Part of the fun.
Check your filter regularly.

Skip Chernoff · « **Reply #3 on:** August 07, 2018, 06:41:05 PM »

Thanks for your response. My stunt fuel for "modern" engines is 1/2 castor 1/2 synthetic. For Foxes and older types it's full castor. For modern ABC engines it's mostly Klotz Techniplate II. Thanks for the tips on filtering I'll follow your lead. Cheers,Skip

Chris Fretz · « **Reply #4 on:** August 07, 2018, 06:41:33 PM »

I had good luck straining the fuel with automotive paint strainers.

Skip Chernoff · « **Reply #5 on:** August 07, 2018, 06:43:16 PM »

Thanks Brent for that explanation,Cheers,Skip

Skip Chernoff · « **Reply #6 on:** August 07, 2018, 06:44:19 PM »

Chris is the automotive paint strainer "fine" enough??

Chris Fretz · « **Reply #7 on:** August 07, 2018, 06:51:35 PM »

Quote from: Skip Chernoff on August 07, 2018, 06:44:19 PM

Chris is the automotive paint strainer "fine" enough??

It took the lint out of my fuel when I was clogging filters left and right 2 yrs ago. Didn't clog the filters after that for me.

Perry Rose · « **Reply #8 on:** August 08, 2018, 04:56:14 AM »

Castor from Bulk Apothecary is clean.

C.T. Schaefer · « **Reply #9 on:** August 08, 2018, 05:30:16 AM »

My pal Doug turned me on to this. A small auto or lawn equipment plastic filter. Paper element. Use it on the outlet side of your dispenser. Since i have an old school type bulb I slide the filter off and fill the bulb then plug it back on to fill the plane. Many gallons used with no fuzz in the filters! TS

Scott Richlen · « **Reply #10 on:** August 08, 2018, 05:56:40 AM »

[quoteA small auto or lawn equipment plastic filter. Paper element. ][/quote]

Do you mean like an auto or lawnmower fuel filter? Can you provide a part number or some kind of specific example?

Thanks.

Chris Fretz · « **Reply #11 on:** August 08, 2018, 07:25:23 AM »

Just curious Skip but you don't use a filtering method on the end of the syringe? Easier to clean that filter every once in a while than all the filters on the airplanes.

Skip Chernoff · « **Reply #12 on:** August 08, 2018, 12:48:10 PM »

Thanks to all for providing this information.

Fredvon4 · « **Reply #13 on:** August 08, 2018, 12:50:58 PM »

I have combinations of cheap RC Car fuels and all components to blend my own mixes

I try to make the expensive Nitro last as Torco's prices have close to doubled the last three years...on sale 1 gal of 30%N RC car fuel for $15 is a good base to play with and I just assume 12% to 15% oil

I mix in 1 liter Batches using Metric math....too easy

Every batch goes into a NEW clean Metal can I buy on line with good caps
Every batch, once blended, goes through a Good Napa Auto Fuel filter....the biggest one with 1/4" in and out I can find
Yes Virginia I use a Power Panel Fed Electric pump to move the liquid

Torco 100% Nitro
Torco Methonal
Riche's brew sourced UCON LB 625 synth oil
Sig Castor
Sig sourced Klotz Techno-plate
Rand Smith Aero One additive

Most of you 1/2 guys need to pay attention close.... Tower and Hobbico NO LONGER produce 1/2a fuels

and I am not complely sure what caused the current Zero production of Nitro

But I have been buying Ebay Torco Racing Boat fuel (40% to 60% N) as it is cheaper that a pure gallon of 100% Vitimin N and I have the math skill to blend it to what I need

Bottom line is Post blending good filtering is a GOOD thing

mike londke · « **Reply #14 on:** August 08, 2018, 04:13:53 PM »

Fredvon, where are you buying metal cans? thx

Dan McEntee · « **Reply #15 on:** August 08, 2018, 04:24:16 PM »

The lint isn't in the alcohol, it comes from the castor oil. The castor bean is a relative of the soy bean, and you can make anything from a hamburger to a soda bottle to a sweater from soy beans. Fibers can be extruded from castor bean oil also. It may have to do wit the amount of processing the oil has been through, as I seem to run hot and cold on fibers building up in filters. I find them most in the filter that I have on my syringe when I draw fuel. That is the way I have leaned it to be from several sources, internet research and reading the subject posted on here at least three or four times.
Type at you later,
Dan McEntee

Fredvon4 · « **Reply #16 on:** August 09, 2018, 11:45:15 AM »

Mike there are several sources...I used to get good cheap 1 gallon cans for a local Sherwinn Williams but they jumped price to unreasonable

After searching I settled on: http://www.thecarycompany.com/

The Cary Company is your source for Raw Materials, Packaging, Absorbents and Filtration Products.

I buy 1 quart round with caps
1/2 Gallon square with caps
and 1 gallon square with caps

Well That sux , I just looked , and the three items I ordered in 2016 are NOT sold by the each now...looks like minimum is 12

No sweat, google, is your friend ----at the time I found about five on line sources...I used Cary as their shipping was cheapest

john e. holliday · « **Reply #17 on:** August 09, 2018, 12:04:26 PM »

Save your cans that had Acetone, paint thinner or what ever in them.

Fredvon4 · « **Reply #18 on:** August 09, 2018, 01:44:06 PM »

Doc when I started that was what I was doing..... for some reason a MEK, or Lacquer Thinner, or Acetone Quart or gallon can.... long shelf life always seemed to have a lot of Rust inside...NOT all and I did reuse several....Initially I was buying some paint a local Sherwin Williams and they had square Gallon can for like $3.99..... but a year later the same can was 7.99...my on line source had wider variety for under $3 each

sadly they now only sell in sets of 12....still good cost per each but do not need a case of any empty container

BTW I have a LOT of expensive Yard equipment that I only run Store bought no Ethanol gas in....horribly expensive even on sale for $4.89 per quart...However...each of these quart cans NEVER rust...I assume the 2 stroke oil content

Dave Harmon · « **Reply #19 on:** August 10, 2018, 12:20:53 AM »

I looked at the Cary site and the round plastic gallon jugs are pretty reasonable.
Get the proper cap though....
These look like the jugs Morgan uses (Cool Power etc)

peabody · « **Reply #20 on:** August 10, 2018, 06:44:29 AM »

Plastic fuel jugs allow water to enter the mix...
Best stored/used from cans, although if you burn more than a gallon annually, the water won't be a problem with plastic.
Enjoy

Fredvon4 · « **Reply #21 on:** August 10, 2018, 01:14:40 PM »

Yes absolutely storage is TIME relevant

Opaque metal or plastic is good for Nitro that degrades from UV in light
Most plastic jugs are air tight enough to prevent H2O ingress to the hydroscopic methanol

My first ever Torco Nitro-methane gallons came in clear plastic jugs... Now last two were in stouter Opaque white jugs

Banking for future with more and more limited availability of Glow fuel...I optimize my storage and labeling

Those of you who burn several gallons a year practicing and competing.... well hell, I have observed a full weekend in full sun, high heat, open gallon and no noticeable degradation of the fuel and performance....my takeaway is that any UV or Humidity degradation is very gradual and NOT a big problem for a pilot flying a lot and consuming the fuel pretty fast

Chris Fretz · « **Reply #22 on:** August 10, 2018, 02:30:04 PM »

When reusing empty gallon fuel jugs what do you guys use to clean them out with? Mine always have dirt in the bottom.

Dave Harmon · « **Reply #23 on:** August 10, 2018, 02:44:56 PM »

Quote from: Chris Fretz / Formerly known as #Liner on August 10, 2018, 02:30:04 PM

When reusing empty gallon fuel jugs what do you guys use to clean them out with? Mine always have dirt in the bottom.

None of my reused fuel jugs have dirt in them and never have.
Of course....the cap is always on!
But....if it did I would swish some methanol around in there to get the big chunks out.
Filter at the bottom of the jug....on the syringe/pump...and in the airplane.

One thing though......if your jug does not have a set of Du-Bro fittings on the cap....your syringe can/will pick up dirt and track it into the jug.
This is what I have and the syringe tube never touches the ground and the jug is never opened unless I pour in some more Blast.

BTW....the other day someone mentioned Formost filters and other products.
I got some of their filters and they are very small but have a large filter screen and tube for good flow. They work very well on the Rojett 67.

Brett Buck · « **Reply #24 on:** August 10, 2018, 07:00:49 PM »

Quote from: Fredvon4 on August 10, 2018, 01:14:40 PM

Those of you who burn several gallons a year practicing and competing.... well hell, I have observed a full weekend in full sun, high heat, open gallon and no noticeable degradation of the fuel and performance....my takeaway is that any UV or Humidity degradation is very gradual and NOT a big problem for a pilot flying a lot and consuming the fuel pretty fast

Heat doesn't matter at all, near as I can tell. as long as the cans are sealed. UV definitely does have an effect, but as you say, it takes longer than a few days.

Brett

Skip Chernoff · « **Reply #25 on:** August 11, 2018, 06:11:51 PM »

I must have gotten a pretty bad batch of castor oil for my last mixing session as I've never had this much trouble with the lint in my filters. Today I took out my ST 60 powered Strega and I noticed as soon as I started her up she seemed to be leaner than usual. After one flight I took her off the lines and pulled the filter. It was filled with the "lint". After removing the junk the engine ran great. I'm filtering all fuel before anymore flying sessions.

Dan McEntee · « **Reply #26 on:** August 11, 2018, 08:08:49 PM »

Again, it is not "lint" in the fuel, it's a natural process and is sort of extruded by the filter screen as it passes through your fuel line filter. If you "bad" castor, it would probably show in the quality of your engine runs. As long as I have been flying stunt ( a REALLY long time now!) i have experienced this with just about every brand of fuel I've used that had castor oil in it. To me it's a minor inconvenience to get the protection that iron P/L and ringed engines need. The addition of some synthetic seems to help the situation so maybe you might want to up the synthetic percentage a bit. read my first post, #17 I believe again. It's just a natural process.
Type at you later,
Dan McEntee

Chris Fretz · « **Reply #27 on:** August 11, 2018, 08:39:37 PM »

Quote from: Skip Chernoff on August 11, 2018, 06:11:51 PM

I must have gotten a pretty bad batch of castor oil for my last mixing session as I've never had this much trouble with the lint in my filters. Today I took out my ST 60 powered Strega and I noticed as soon as I started her up she seemed to be leaner than usual. After one flight I took her off the lines and pulled the filter. It was filled with the "lint". After removing the junk the engine ran great. I'm filtering all fuel before anymore flying sessions.

Skip I just made a gallon and ran it thorough a paint strainer, I didnt have any junk in mine unless what you are seeing is really fine. If you think the castor you are using is a problem try the Sig Castor, it seems clean, maybe cheaper than what you are using to??

Chris

Skip Chernoff · « **Reply #28 on:** August 12, 2018, 05:52:08 AM »

According to Dan here it is just a natural process that would occur with all castor. Chris, I think that I'm just noticing the problem now because for years I mixed R/C fuels that used Klotz Techniplate II a synthetic with 20% castor in it. The fuel was also mixed at 18% total oil content. The stunt fuel I'm mixing is 1/2 castor 1/2 synthetic at 23%......and the fuel for the Fox motors is 29% pure castor! I'll pay more attention to keeping my fuel filtered and cleaning my filters before each flying session. BTW Thanks Dan for your input. Cheers,PhillySkip

Dan McEntee · « **Reply #29 on:** August 12, 2018, 06:06:04 AM »

For Fox engines I wouldn't go less castor than the 50-50 mix you are using. Mainly because I like the smell! When I worked at the local hobby shop, I used to see lint in R/C carbs from R/C cars all the time. A customer couldn't figure out why he couldn't draw fuel or some other running problem and I would almost always pull a wad out of the carb. Same with airplane engines. The lint is NOT in the components of the fuel, it is being made at the screens of the filters or where ever the fuel can pass through a tiny opening. If you did not run a filter, it would collect at the needle in the spray bar and clog it up tight. That is why I run a filter, mainly, to give that sort of thing a place to happen before the needle valve. And it is why the direction of the filter is important. One side has more volume or space than the other, and that side should be toward the tank. That way, as junk collects you have more room for continued fuel flow. You just have to check your filter regularly, which you should be doing also, like when you check your engine mounting bolts.
Off top practice for Paducah!
Dan McEntee

Fredvon4 · « **Reply #30 on:** August 12, 2018, 01:08:25 PM »

This is an interesting thread for my because I am much more a motor head that a competent pilot

and I have a LOT more time tinkering (tuning, rebuilding, hopping up) with 2 and 4 stroke engines from .049 up to 560CI

All ---!!! Need CLEAN fuel, and every one has a defined fuel metering orifice size....obviously a Cox, Cyclon, Norvel .049 needs to pass fuel through a very small needle valve...a Honking monster 500+ CI big block Chevy with Naturally aspirated twin Holly 800CF has main jets that are huge in comparison...BUT BOTH require fast, clean, free flowing fuel

whats the point?

??...

I personally find ALL the model airplane filters wanting...but I do use them as insurance... but when dealing with my fuel, be it store bought, or self made...I use very large auto fuel filters of know pedigree.... Hell I have even filtered large amounts of racing fuel through a gang of OIL* filters.... (55 gallons for Nitro Meth blends...in to go cart 5 gallon jugs)

* oil filters actually have a lower mesh filter size

I know some think a coffee filter is cool and cheap or a cone shaped paint filter.... I assure you, viscosity of paint and coffee are very wide apart and it seems logical that coffee filter is good....but BOTH are wrong for the liquid WE are filtering....

Glow fuel is NOT water with some caffeine.. it is much MORE viscous
Glow fuel is NOT thinned Paint ...It is Much LESS viscous

Auto zone
Napa
O'Reiles
What ever, they all carry a large line of FUEL filters and mostly they all will pass 2 stroke oil laden fuels with a great amount of filtering and still have fair i great flow rates

Lauri Malila · « **Reply #31 on:** August 12, 2018, 01:33:18 PM »

The problem with this "lint" or fibrous particles in castor fuel is, that it's caused by bad quality castor oil. Once it starts happening, it won't stop. More fibers will form after filtering. At least that's what I have noticed. Then it's better to change oil supplier. L

Skip Chernoff · « **Reply #32 on:** August 12, 2018, 05:39:11 PM »

Ok Ok we all seem to agree that the castor causes the problem. I've been using Klotz "Benoil" for my castor. So where do you get "good castor" that is more refined and won't clog your filters? Is "medicinal" castor better than say Klotz?

As a side note today I pulled out a plane I haven't flown in ages .An old Sterling Skylark refitted with a Tower Hobbies 40. Same crap different day.....the filter was filled up the same as my other planes. I'm beginning to think that I just might start mixing my fuels with Synthetic only and be very careful with setting the needle valves. I'm spending more time futzing with engines than flying!

Dave Harmon · « **Reply #33 on:** August 12, 2018, 06:19:05 PM »

Here's still another view......
When the VECO 61 came out in 65' I got one and wore it out several times.
Then after K&B bought the engine business from Henry Engineering, I continued to use the K&B 61 which was essentially the same engine with a few improvements.

Living in the LA area at the time....I ran into Clarence Lee the designer of this engine and he insisted that 15% nitro and 22% straight castor was best in this engine. Since way back then he has printed this several times in his mag columns.
From 65' until 85' and occasionally more recently....I successfully used these engines using 22% straight castor from many sources.

I always mixed my own fuel as the ingredients was readily available locally.
I have no idea what brand the castor was but I never used a filter back then and to this day I have not had a 'lint' problem or even dreamed about an extrusion problem with the castor.....never heard of it before now.

Now listen....I am NOT saying that all this does not happen....but it has never happened to ME having flown thousands of flights using glow fuel...about 3 thousand flights in the last 4 years....with or without filters.
Or to anyone else I have known.
I'll bet this is because the coffee filters work so well....right.

These days I have a couple bottles of SIG and Morgan castor that I am going to use up then change to the bulk castor.
Several guys locally made a buy of the bulk castor and it is working well.

BTW.....the bottles of castor I have from SIG and Morgan have never been opened but there is dirt collected on the bottom of the bottle....the inside that is!
As long as I don't shake it up the dirt can just lay there until I use the rest of it.

Lauri Malila · « **Reply #34 on:** August 12, 2018, 11:38:02 PM »

Benol should be ok, but better option is Maxima #927. L

Skip Chernoff · « **Reply #35 on:** August 13, 2018, 05:46:08 AM »

Lauri, I Googled this oil and it is not pure castor. It is a mix of Castor and synthetic .Kinda like what you would use in a Kart or 2stroke off road bike.Is this what you use?

Skip Chernoff · « **Reply #36 on:** August 13, 2018, 06:02:47 AM »

Dave I've never had this issue before until I got back into "Stunt" 3 years ago and began using in line fuel filters.

Lauri Malila · « **Reply #37 on:** August 13, 2018, 10:22:28 AM »

Quote from: Skip Chernoff on August 13, 2018, 05:46:08 AM

Lauri, I Googled this oil and it is not pure castor. It is a mix of Castor and synthetic .Kinda like what you would use in a Kart or 2stroke off road bike.Is this what you use?

Hi Skip,

Not really a mix, more like a modified castor oil. So it's mostly castor with some additives.
I use it like castor, mix 1/4..1/2 in total oil mix. Alone it has slightly high viscosity for my use.
It leaves clearly less residue than Benol. L

Skip Chernoff · « **Reply #38 on:** August 14, 2018, 12:10:54 AM »

Thanks, I'll buy a quart and try it out.