BuzzBomber

My Feedback: (4)

I am in need of a new fueling system for my field box (the old surplus veterinary syringe has developed a leak, and I am growing to despise my DB six shooter). I've got a few norvels sitting around, which I intend to find homes for shortly, and IIRC, rubber in the fueling setup apparently causing glow plugs to foul. I did a search, but couldn't find the thread that I thought had settled this issue. I *think* the consensus was natural rubber=bad, synthetic rubber=okay. I was planning on just picking up a sullivan 4 oz bulb for 1/2a fueling tasks, and these are neoprene rubber, so I'm hoping they're usable--I really don't want to have to pay shipping on a stinkin' $5 fuel syringe.

William Robison

My Feedback: (3)

Matt:

I had a "Six-Shooter" pump a long time ago. Hated it from the first time I used it.

But I'm happy with the unit supplied by Hobby People/Tower/Etc. with the black casing and the hand crank.

Bill.

Andrew

Matt --

The FAQ from NORVEL regarding rubber contamination is [link=http://www.norvel.com/t002.html]here[/link]. The Sullivan tubing that comes with the fueler is neoprene -- I think the bulb is natural rubber.

You might check with your local pharmacy, vet or WallyWorld for a small nalgene or polyethylene squirt bottle with a tip to accept fuel tubing. 8 or 16 oz. would be sufficient for a day's flying.

the "other" Andrew

BuzzBomber

My Feedback: (4)

Bill,

That's the one I was planning on replacing the six shooter with. Seems everybody's got one and likes it.

Andrew,

Could it be that Sulivan recently changed the formulation of their bulbs? Tower's site shows them all being natural rubber in a brick color, but Sullivan's website shows them in various sizes, color coded by capacity, and claims they're all neoprene, except for the gasoline bulb. I don't know, I just say the red one at the LHS and assumed it was neoprene rubber[sm=confused.gif]. Here's a link: [link=http://www.sullivanproducts.com/FuelPumpsMainFrame.htm]Sullivan[/link]
EDIT: Forgot--good tip on the squeeze bottle--I may just look into that if the bulbs ARE natural rubber.

BMatthews

Back in my early days I had a Sullivan type bulb (It was Perfect brand at that time). I saw all the folks having problems and figured out pretty quick that it was the fuel residue until I could not smell any alky when puffed lightly into my face. What I did was use the bulb and at the end of the day spent a minute or so squeezing air into and out of it. That evaporated all the alky and nitro and left just the oil. That same bulb lasted me for well over 5 years. But don't forget to do the drying bit even once or it'll take a year off it's life.

Hopefully the new ones are synthetic rubber or silicone rubber

SST

My Feedback: (2)

I have a Sullivan bulb and my Norvel plug lasted about 4 flights. I'm switching to a syringe. You can get the large ones from Valley Vet Supply up to 140cc.

flyinrog

My Feedback: (1)

look at the LMH (Lite Machines Helicopter) filler bottle on their site it holds enough to fly all day, all you do is fill it up and switch tops when you want to fill a tank..Rog

Lynn S

I found a one ounce syringe at walmart in the kitchen utensels section.
Fuel tubing fits right on the end and a short piece of alum tubing on the other end of the tube.
I can fill my 2 oz tank with one or two measured squirts in about 30 seconds.
If I want to use 1 ounce or 1 1/2 ounce I can measure it exactly as I want it. This makes it easy to adjust engine run time with my non throttle engine.
I made a pickup tube to go to the bottom of my 1 qt fuel bottle. I just insert the end of the tube into a fitting I made and draw the fuel out into the syringe.
This syringe has given me no problem with my Norvel engine. I have a sqeeze bulb, I never use it. There is no way to measure how much fuel I draw out or put into the plane.

cali_dream

Rubber degrades when exposed to model fuel, and the level of nitromethane in the fuel will play a big role. 35 nitro will degrade everything faster, including rubber. The temperature in combustion of small motors is lower than bigger motors, so what types of chemicals are consumed in the combustion are different. There are some die-hards who swear they use rubber bulbs with no problems, and I have no reason to doubt them. But there are plenty of others who have said getting rid of the bulbs solved their plug-fouling. All of us know that modelling is not always an exact science, and it's better to stick with the things that are working. Be careful that some syringes actually have a plunger that will degrade, too. Guys who leave fuel in the syringe for a long time, all day, will see the concentration of rubber increase as it degrades more. Also, putting fuel from the bulb or syringe (with rubber plunger) back into your fuel bottle will gradually increase the concentration of rubber as the fuel in the bottle is used up. So you might use a bulb with no problems for the first few tanks, but kill one plug each flight when the fuel bottle is almost gone. Better to avoid rubber!

Ed Stevens
NORVEL, Ltd.

Japanman

Not wanting to seem to be contradicting you, Ed, but I have often wondered if the guys who use bladders have plug fouling problems- I have not heard of it myself.

J.M

BuzzBomber

My Feedback: (4)

Right--the verdict is in. I shall procure a poly squeeze bottle, since I can get it local, and don't want to pay shipping on JUST a syringe. Or, maybe I could order a buncha spare plugs to amortize the shipping charge. Either way, I'll stay away from the rubber bulb now.

combatpigg

My Feedback: (3)

HEY JM! The guys who use bladders blow the elements out of the plugs before they have a chance to foul. I have never accused a silicone bladder of fouling a plug, but I wouldn't be able to tell what to look for. I have run bladders for years, and most plugs die a slow death.

ZAGNUT

My Feedback: (1)

CP, what is this silicone bladder you speak of?? i never thought there was an alternative to the latex tube i use.


dave

combatpigg

My Feedback: (3)

Hi DAVE! My mistake, I meant to say LATEX. I have seen silicone that would inflate, but the pressure is too high.

Japanman

Hey Zagnut,
a while ago you mentioned using balloon tanks- Have you ever come across a silicon membrane/ balloon material that could be used inside a 1/2A sized tank ala Jett bubbless tanks?

J.M

cali_dream

Well I am far from an authority, I have wondered about the bladders, too. My only guess is that anyone using a bladder is running the motor pretty lean (hot) because of some kind of competition situation. The engine would run a lot cooler at 7000 rpm or at idle.

Definitely hard core performance guys are less concerned about blowing out glow plugs, they are used to going through them pretty quickly.

The other thing is that the fuel sitting in the bulb and decanting the fuel from the bulb back into the fuel bottle after a day of flying seems to be a big problem. Time is what causes the decay, really, so a minute or two in a bladder might not be so bad.

I admit it's an educated guess really, we never did any complete chemical tests on the issue. But it is always good to avoid any possible problems lest that perfect Saturday morning be spoiled . . .

Ed at NORVEL, Ltd.

William Robison

My Feedback: (3)

JM:

I think you mean "Tetra" on the bubble less tanks.

To make your own you can use surgical rubber gloves, they deteriorate just the same as your surgical tubing pressure bladders though, shouldn't run one more than a month or two without changing it.

You can also use the disposable polyethylene gloves, they have an indefinite life but they are more trouble to seal the the fittings inside the tank.

With either material you have to give the clamping screw of the plug and the vent pipe end extra care, as they can puncture the internal bladder if not carefully rounded on the ends.

Bill.

BuzzBomber

My Feedback: (4)

Not to distract the thread from the bladder conversation, but I just wanted to update on my situation--I looked over the Sullivan 4 oz fuel bulb at the new Hobbytown tonight, and it does indeed say on the package, "all natural rubber". Ponderous, as the web page claims they are constructed of neoprene. However, Sullivan does peddle an 8oz polyethelyne squeeze bottle with a check valve and two outlets--I suspect I'll be adding that to my next order from "the evil empire", aka tower.

Bipe Flyer

I have a plastic squeeze bottle that was used for hairdressing, but I mostly use a hand pump similar to the one in this picture. Mine is about 3 turns to an ounce.

ZAGNUT

My Feedback: (1)

bill, jett makes the "jett bubble" alternative to the tetra tank.

every time i try to use the polyethylene gloves or bottle liners i end up with leaks. i guess the material is just too thin and very sensitive to over filling. an alternative that i have yet to try is the latex-free condom that looks to be the same material as the vinyl examination gloves. this material has a bit of stretch to it and holds up well without rotting like latex. this should also allow quite a bit more than the 20cc i get from a glove finger.

i guess for high pressure without the complications of the bubbless tank i'll still be using latex bladders. i toss them after a day of flying so i haven't seen any problems from contamination. just wish there was some synthetic material with the same properties and compatible with gasoline.


dave

Andrew

Matt --

It is still quite likely that Sullivan has switched to neoprene -- given long distribution lines and inventory roll over, your hobby shop may simply have old stock on the shelf. When they reorder, the newer bulbs will probably be as advertised. Sullivan is a reputable company and would have little to gain in the modeling world with misinformation.

the "other" Andrew

ZAGNUT

My Feedback: (1)

how about those ear-washer bulbs i remember being tortured with as a kid??
if someone still makes them and they're synthetic they would be perfect for 1/2-A fueling needs.


dave

Japanman

Nice Call about the Condom, Zagnut.
I am going to have fun embarrassing the heck out of a Japanese shop assistant while going through the boxes (and asking lots of questions)!
That sounds like a good material to try.

J.M

gcb

Just make sure the wife doesn't squirt fuel in the kids' ears.

George

ZAGNUT

My Feedback: (1)

just look for durex elite

dave