Nylon filters with metal screens

[Al Rabe]

I could use some more nylon filters with metal screens like I've used for the past 45 years.  I have never been concerned with leakage from the push together nylon filters (Sullivan?).  The only problems that I've ever had were with those screw together metal filters with some sort of [plastic screen.  These, on occlusion have caused some serious problems and resulted in ruining a Saito 72.  I wrote about these filters and trouble shooting them on Stuka years ago.

Al Rabe

[Motorman]

The screw together Dubro filters are nice and have an O-ring seal. If you could get a stainless steel screen in one of those win win.

MM

[john e. holliday]

Eric Rule at RSM Dist had some blue plastic fuel filters that I use.   Guess I need to check and see if he still stocks them.


Don't know if they are the same or not:   "Crap Trap" filter   #SU187  at $4.90 ea.

[Norm Furutani]

This is a nylon body, metal screen filter from FourMost. http://www3.towerhobbies.com/cgi-bin/WTI0001P?I=LXBNU8&P=8#tech. Fourmost, Ralph Cooney, makes nice stuff!

Norm

[Al Rabe]

Norm,

Sounds and looks fine.  I ordered 3.  Thanks

Al

[RknRusty]

I like the Fourmost filters for my 1/2A fleet. But I wondered if their passage was too small for a 35 sized engine, and so use the Dubro with the nylon screen and o-ring. As long as you don't install it backwards, they work well and stay tight. I like that they have a mounting hook if you so desire to anchor it. Like any of them, if you install it backwards the inlet can become occluded in short order when you're using an old metal tank that's shedding rust and flux.

If you have a cramped space on a cowled engine, the small Brodak all aluminum filter works great, but it's hard to look at and see which way the flow should go, and it matters even more than with the bigger Dubro.


I love the Fourmost check valves that look like the green filter, but is red. Every 1/2A plane I build has one in the tail of its bladder, making filling quick and neat. I have some old ones that still work. If they start leaking, a quick flush fixes it.

[Lauri Malila]

Hi.
Sullivan craptraps are known to cause running problems with engines with low fuel consumption, like Retro's and MB. Propably it is because of too big internal volume, at least I have noticed several times that air bubbles remain trapped inside the filter when engine is running. Changing to a smaller filter has allways cured the problem.
It's also easy to shorten a craptrap filter, leaving just one mesh, usually the coarser one.
I use std craptrap only in air intake line of fuel tank, and in filler bottle/syringe.
I also noticed recently that the the aluminium ends of craptraps start corroding and forming something that resembles oatmeal when they are in contact with fuel for longer periods of time. Maybe it's because of fuel I use, or perhaps Sullivan uses some crappy alloy for making them. L