hookedonrc

I have a Four Star 60 ARF that needs reinforcing on the bottom behind the firewall. Since this came assembled, they put in the fuel tank tray and I forgot to try to put in some triangle stock when building. I want to get the epoxy down to the back of the firewall, but it is quite a ways away from it. Any suggestions for getting epoxy into small far away places like this? I want to put a bead along the bottom of the firewall.

klhoard

My Feedback: (10)

Heat a bowl of water in the microwave.

Mix up some epoxy in a smaller bowl.

Get about 2-3 feet of fuel tubing.

Float the small bowl of epoxy in the hot water until the epoxy turns to liquid.

Stick one end of the fuel tubing in your mouth.

Stick the other end of the fuel tubing in the epoxy.

Suck. . . . but not too much!! I've never tasted epoxy and I bet you don't either.

Put the fuel tubing where you want and Blow. . . .

For added strength, you can then sprinkle ground up fiberglass (I make mine with a Dremel Tool) onto the epoxy or position your triangle stock in place.

I would discard the tubing that had epoxy in it. . . . won't help any future engines.

Hey, desperate times require desparate measure, right??

Charlie P.

A plastic syringe and a bit of tubing on the nozzle can be used (clean with acetone afterwards). (West Systems sells them).

Charlie P.

tinman

My Feedback: (13)

if you poor a bit of epoxy on back of firewall......use your heat gun and it will flow into all the cracks and spaces np. this works great.

hookedonrc

Thanks tinman: I will try your approach. I am not sure I want to suck heated epoxy up into a fuel line, but I do appreciate the ideas. And I am not sure if one can buy syringes. (Please let me know where if this is possible, I just have never tried it. ) Anyone out there that might have another idea let me know. Thanks guys.

Wayne H

You could drill two 1/4" holes in the bottom of the fuselage, somewhat close to the firewall. Through these holes, can add your reinforcing epoxy. Keep the plane in a vertical nose down position until the epoxy set then cover the holes with tape or covering. If you make the holes big enough, you could maybe also add the triangle stock too. Don't go too big with the holes, you don't want to compromise the strength of the firewall.

Mike Noin

Try visiting a local veterinarian, and ask for some syringes that they have used for something that you can clean and then use for the hobby. I have done this and gotten some rather large syringes. Make sure that you make it clear that you do not want the needle part of the syringe when you ask. Another place is the local hospital, I have asked for a syringe there before and the nurse gave me 2 of the largest ones they had brand new still in its protective plastic tube with lid.

Also, heating up epoxy with your heat gun will make it cure a little faster and a little harder because when you heat it all of the bubbles trapped in the epoxy escape and you get a clear flow in stead of one with sporadic bubbles throughout. The epoxy should become almost like water when you heat it up, this method works great for the implied task. I always heat up my epoxy before I use it on any application. If I find it is too thin after I heat it I just wait a minute to let it start to thicken and then start to apply it, still get the benefits of a good cure and a bubble free set.


Good luck

BALSABRO

My Feedback: (3)

Turkey injectors work great

nascarfan88

If you can get an acid brush down into the area use a long dowel rod shoved up inside the brush. I also cut the bristles of the brush off short so it's stiffer.

hookedonrc

Nascarfan88: THANKS.... I am headed to the garage to try your suggestion. I do have the acid brushes and some doweling. For the others suggestions I appreciate your input, and knowing I will probably have to do this in the future, I will begin my syringe search. I will also try heating the epoxy.

Thanks again everyone.

hookedonrc

UPDATE: Well it's done. The acid brush with dowel worked perfectly. However, I didn't have a dowel, so used a 1/4" square stock I had sitting around. Pushed the handle of the brush into the 1/4 stock about 1/2 inch, taped it in and trimmed the brush as suggested. I got the epoxy just where I wanted it. It's drying and as soon as finished, I will cover and fly!!!

I am sure I will use each technique some time. Still not sure if I am brave enough to suck hot epoxy into a fuel tube, but you never know. This all started when I pulled out the entire landing gear shelf on a high grass landing last week. Didn't hardly do any damage since when it was assembled, hot glue was used and I could find only 2 places where it was actually attached. Came out just like a puzzle piece.

Be CAREFUL with this ARF if you get one. I did a lot of mods to correct things I didn't like with it when I put it together. And it was only my second plane.

Anyway, THANKS for everyone's help here.

nascarfan88

hookedonrc

We use the old acid brush trick building real business jets. Shorter you cut those bristles off the stiffer so they make a perfect tool for cleaning stuff too. Also, if needed the handle of the acid brush bends real easy so you can get the proper angle you want.

Everything on real aircraft get sealed - fuel tanks, cabin, etc, etc.
so the brushes are a very cheap tool for doing this.

Glad it worked for you.

Highlander

you can buy syringes at any feed store , they sell them and the needles for cattle and other livestock.

Highlander

klhoard

My Feedback: (10)

Awwww, I wanted to hear what epoxy tastes like!!

Just kidding!!

Actually, I like the epoxy brush trick better. Doesn't ruin good fuel tubing.

Yes, you have to be careful with ARF's. The people buiding them aren't going to fly them.

hookedonrc

klhoard: I have visions of being in the ER with my wife trying to explain how I glued my mouth shut. You know now that I think about it I wonder if she would even take me?

klhoard

My Feedback: (10)

ROFLMAO!!!

I wouldn't take you either if you glued your mouth shut with 30 minute epoxy!!!! I'd grab the digital camera and start calling our buddies over!!