Originally Posted by Low_Cal

DA sells headers made by other companies.

I remember hearing that the blue teflon tape from Lowes or Home Depot worked the best.

My solution was just to get a bigger engine and not use a tuned exhaust; the weight comes out the same.

The flex header on the Da60 I purchased leaked also. No biggie, I used Monster tape and re-wrapped with no issue, that's the blue tape.

Originally Posted by crossup

Only an idiot would say the idea behind flex header is bad.
But only someone who does not understand metal working would say they have to leak.
So if wanting a working product that requires only technology perfected 50+ years ago is asking too much, I'll just go to McMaster-Carr or whoever, buy the materials and make my own THAT DONT LEAK. Brazing is not that hard and its not that hard to leak test things either.

All my planes have things you can't buy on them and all of them have improvements that even Dalton doesnt put in their kits, so why Russo would throw ("todays modeling world people want to just bolt on the parts and fly")that kind inane justification for leaking heading out there just makes me wonder why he would want to alienate someone who he has no clue about their building skills.
Anyone doubting I can build my own headers need only look at whats in my current at home shop...soon to be replaced by 1200 sq.ft with all my serious metal working equipment moved into from its current location at my job's shop.

Defensive, yep, I hate being lumped in with the current crop of ARF only "builders" because I've tried a few while living in a townhouse with very limited building space. As to building, I doubt I'll be building either Carden or Dalton because I hate foam wings and own only one plane with them but it will get built with balsa wings

I agree with Robinsp, you need to have a couple beers and relax on this. RC planes are rarely turn-key systems that work perfectly without some tweaks, unless you buy an RTF. That's the way it is, too many possible combos of airframe, engines, and other equipment.

You can make this work though. I have a pretty complete shop also, but I wouldn't build my own headers unless there was no other way. Too much work! Easier to buy something close, and modify that as needed. To do a good job building your own, you would need access to a very expensive mandrel bending machine; no way to make a decent 90 deg bend without that. You can definetly make small corrections to existing bends though, just using a cheap harbor freight die bender.

I was merely disappointed that headers purchased from a quality company leak..then I find here that its 'normal' that and saying that is a pitiful comment given the current state of RC technologies earned me T. Russo's comment to the effect that I'm a lazy ARF'er expecting too much.
THAT does set me off.

Think about it, an unexceptional individual can make a leak free exhaust with enough effort but a company whose business is making exhausts can't? We're not talking about modifying something to fit or to do something it was not originally intended to do, the exhaust headers job is to conduct exhaust to the pipe or canister not leak it into the cowl. From the mess I'm getting we are not talking about a pin hole either....

As to needing an big dollar tubing bender...sure some folks might have a problem with that but I live and work in Annapolis....so I can go to Kato, Carter Fab or a couple other shops that make SS pulpits and tubing hardware(all 1" same as my headers) and very likely get my two simple bends for free having feed work to all these shops since 1989. Worst case is bring a case of beer to one of the fab guys at closing time and get it done off the clock. Don't even need to try to fake it with my stuff...

Making new headers from scratch is a last resort, modifying some 75mm drop headers already on hand is likely my easiest solution as I can likely do that by heating the aluminum involved to 450 in a oven and hot bending to the proper angles. Heliarc it back to the flange and I have no flex joint to leak or fail.
After 3 35% planes with not even microscopic leaking I'm not going to bandaid this one unless I find the leaks are in fact only pinholes, which is pretty unlikely. The headers have to come off regardless of how I deal with this so we will see....

Originally Posted by Low_Cal

I agree with Robinsp, you need to have a couple beers and relax on this. RC planes are rarely turn-key systems that work perfectly without some tweaks, unless you buy an RTF. That's the way it is, too many possible combos of airframe, engines, and other equipment.

You can make this work though. I have a pretty complete shop also, but I wouldn't build my own headers unless there was no other way. Too much work! Easier to buy something close, and modify that as needed. To do a good job building your own, you would need access to a very expensive mandrel bending machine; no way to make a decent 90 deg bend without that. You can definetly make small corrections to existing bends though, just using a cheap harbor freight die bender.

Such a lot of stress over a tiny issue. KS fittings work fine and dont take much time to fabricate to shape. They be cheaper than spending time in the workshop or running around hiring tools to fabricate parts. You'd have the headers made in the time it took you to write your posts.

Originally Posted by crossup

I was merely disappointed that headers purchased from a quality company leak..then I find here that its 'normal' that and saying that is a pitiful comment given the current state of RC technologies earned me T. Russo's comment to the effect that I'm a lazy ARF'er expecting too much.
THAT does set me off.

First of all my comment about people wanting to just bolt on parts and go fly was not directed at you. I was simply trying to give my observation after working at DA for 5 years of why flex headers are so popular and used in a wide variety of aircraft. We would like to have a solid header that fits in every plane but its just not possible. DA does not make headers, we distribute headers from 2 different manufactures out of Germany that currently offer what we feel is the best products on the market. If anyone has a better design and can keep up with the demand we would consider carrying your product. Like you I am a modeler having built my own planes since I was 15 years old. I have nothing against arf's or people that buy nothing but arf's. There are way more important things in life to do than sit in a garage building planes from kit form. However for me and many others that enjoy building kits thats half the fun. As long as they are enjoying the hobby thats what matters. I am sorry that you took my comment the wrong way and felt it was directed at you.

Originally Posted by crossup

Think about it, an unexceptional individual can make a leak free exhaust with enough effort but a company whose business is making exhausts can't? We're not talking about modifying something to fit or to do something it was not originally intended to do, the exhaust headers job is to conduct exhaust to the pipe or canister not leak it into the cowl.

What you say is true, but the problem isn't limited to rc flying. For example, I'm currently faced with a $2,500 transmission rebuild in a Corvette because GM sourced a six speed manual with cardboard syncros and sheetmetal slidder keys. Tremec made the transmission, not GM. Its a wonderful gearbox though, and can be rebuilt much better. So there you have it . . . its life.

Steve,

I've used the flex headers from DA and the JMB headers. The worst I saw with the flex headers is some discoloration to the tape but it was really a non-issue for me= flew the whole season without any maintenance to the headers. I don't even think about it unless I happen to need to get the cowl off for some reason.

Dave

I run mtw headers (Flex) I flew a season of imac flying this year, probably burned 60 gallons of gas, My tape is discolored but i dont have any exhaust leaks , my motor is a DA-150 with MTW 90 mm drop headers and RE3 tuned pipes . And that is the stock tape on the headers,

Bryon

I have had good luck so far using the following method: First clean the flex area of the header with acetone and a wire brush. Them smear on a good coat of ultra grey permatex and then wrap the header with Nitro Tape from(www.tommytape.com) . After you do this method you are done messing with header leaks period.

1. They also sell the silicon tape at Aircraft Spruce. I've used it on my headers for +2 years.

http://www.aircraftspruce.com/catalo...rescuetape.php


2. Question: how about using the Permatex copper which is good to 700 degrees v the black or gray versions?

http://www.permatex.com/products/Aut...sket_Maker.htm


3. McMaster-Carr sells a mil spec teflon tape that makes wrapping the header much easier. Premium 1" wide works for me.

http://www.mcmaster.com/#pipe-thread-tape/=jx8js7



Tony, as always we appreciate your input.

Originally Posted by Ground Pounder

1. They also sell the silicon tape at Aircraft Spruce. I've used it on my headers for +2 years.

http://www.aircraftspruce.com/catalo...rescuetape.php


2. Question: how about using the Permatex copper which is good to 700 degrees v the black or gray versions?

http://www.permatex.com/products/Aut...sket_Maker.htm


3. McMaster-Carr sells a mil spec teflon tape that makes wrapping the header much easier. Premium 1" wide works for me.

http://www.mcmaster.com/#pipe-thread-tape/=jx8js7



Tony, as always we appreciate your input.

GP, I know this is a bit old but I just orderd #3 of from your post and was just wondering if you used it and if you like it. I have never had to change the tape on any of my headers until know.

Thanks, Spats

If you are so capable of brazing together a set of your own headers, then do it. Or use one of the many solutions many people have given you here and stop complaining on Flying Giants about it. Don't try and patronize Tony for simply stating a fact about how the hobby works today and turn it into something it isn't. Once again solve the problem with one of the many ways provided and go fly! After all that IS what our hobby is about;model airplane's whether it be building them, flying in competition, or just for fun. Just get it fixed and go Fly

Originally Posted by Envelope Pusher

GP, I know this is a bit old but I just orderd #3 of from your post and was just wondering if you used it and if you like it. I have never had to change the tape on any of my headers until know.

Thanks, Spats

My first flex header (several years ago) had a defect and would burn a hole through anything. However if the flex is in reasonable shape the mil spec teflon is excellent. After reading this thread the first time I decided that I will use the Permatex silicon plus the mil tape. The Permatex would help to seal any micro holes that might grow plus absorb/deaden vibration induced rubbing.

I still think that the silicon tape is an excellent product and another good option.

BTW I was talking to Dave and he mentioned that we might link up for Wenatchee. That will be a nice event. Now that the Lodi huckfest is locked in for October it looks like it will be a great Sept/October for us.

Originally Posted by Ground Pounder

My first flex header (several years ago) had a defect and would burn a hole through anything. However if the flex is in reasonable shape the mil spec teflon is excellent. After reading this thread the first time I decided that I will use the Permatex silicon plus the mil tape. The Permatex would help to seal any micro holes that might grow plus absorb/deaden vibration induced rubbing.

I still think that the silicon tape is an excellent product and another good option.

BTW I was talking to Dave and he mentioned that we might link up for Wenatchee. That will be a nice event. Now that the Lodi huckfest is locked in for October it looks like it will be a great Sept/October for us.

Thanks for the info!
Yes I am looking forward to Wenatchee and meeting you, I've got a spot reserved. Dave is always such a great help and standup guy. After two setups with Pro-Flos I wouldn't try anything else.

Again thanks, I am going to get some Permatex I like your thoughts on it.

I'm just finishing up a new custom 37.5 Yak and using the EVO 176, Pro Flows and a new 18MZ. I've been closely following Dave's progress for over two years (we fly at the same field). It is a very strong combination. Looking forward to getting it into the air in a few weeks.

Needless to say that it will have Permatex and mil spec tape on the headers.