| Author |
Message |
Wildthings
Samba Member
Joined: March 13, 2005
Posts: 50331
|
 Posted: Fri Mar 25, 2016 2:34 pm Post subject: Re: Heater tube issues |
 |
|
| raygreenwood wrote: |
The melt point of polyethylene is 240° to 280°F.....maximum. These heater ducts melt at about 250°F.
And.....there is nothing "better" about stock heater duct material. Its all polyethylene.
Of course...stock probably fits better.....but the material melts at the same temp. So....you either have excessive heat......or the rock wool heat tube on the inside is too short and does not pass all the way to the cuff allowing heat to leak around and melt the corrugated outer tube. |
Ray, This is a bus forum and not a Type 4 forum. The bus tubes only see the normal outlet temps of heat exchangers, there is no gas heater adding BTU's to the system. The outlet temps of the exchangers can exceed 250°F though. The aftermarket craps melts at a lower temperature than the OE plastic and below the normal outlet temperatures of the heater boxes, no question about it.
Actually the tubes between the Type 4 heat exchangers and the gas heater don't get anywhere near as hot as the Bus tubes as Type 4 heat exchangers don't but out squat for heat compared to bus heat exchangers. Only the tubes between the gas heat and the ducts going forward into the cab see heat from the gas heater, the tubes between the Type 4 heat exchangers and the gas heater do not. |
|
| Back to top |
|
 |
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21507
Location: Oklahoma City
|
| Posted: Fri Mar 25, 2016 3:21 pm Post subject: Re: Heater tube issues |
|
|
| Wildthings wrote: |
| raygreenwood wrote: |
The melt point of polyethylene is 240° to 280°F.....maximum. These heater ducts melt at about 250°F.
And.....there is nothing "better" about stock heater duct material. Its all polyethylene.
Of course...stock probably fits better.....but the material melts at the same temp. So....you either have excessive heat......or the rock wool heat tube on the inside is too short and does not pass all the way to the cuff allowing heat to leak around and melt the corrugated outer tube. |
Ray, This is a bus forum and not a Type 4 forum. The bus tubes only see the normal outlet temps of heat exchangers, there is no gas heater adding BTU's to the system. The outlet temps of the exchangers can exceed 250°F though. The aftermarket craps melts at a lower temperature than the OE plastic and below the normal outlet temperatures of the heater boxes, no question about it.
Actually the tubes between the Type 4 heat exchangers and the gas heater don't get anywhere near as hot as the Bus tubes as Type 4 heat exchangers don't but out squat for heat compared to bus heat exchangers. Only the tubes between the gas heat and the ducts going forward into the cab see heat from the gas heater, the tubes between the Type 4 heat exchangers and the gas heater do not. |
So what:.....who said what we are talking about is type 4 specific?.....not me:
1. The OP did not mention one way or the other whether he had a gas furnace. ..and virtually all the bays had an optional gas furnace of some type. ....which is why....if you note. ...I said IF.....you have a gas furnace.....this is one of the possible causes of it on systems that DO have a gas furnace.
2. Everyone noting....."never seen anything like this".......while I have....and not just on type 4 based vehicles. I simply used my vehicle ...which just happens to be a type 4.....as an example of how it can happen.
3. The outlet air temperature of all VW heat exchangers at the cuff exceed the melt point of the outer polyethylene ribbed tube material. Without having the internal fiberglass or rock wool covered tube extending full length....you can melt the end of the tube
I have seen this in beetle tubes as well. The most common cause with stock tubes is beating the tubes up and knocking the inner tube loose so it slides in one direction leaving a gap at the hottest end. This can also happen when the tubes get soaking wet. The wool inside...whether its fiberglass or rock wool.....gets sloppy and slumps one direction on the inner wire support.....again...leaving a gap that can allow excessive heat to melt the outside polyethylene plastic.
What you need to understand. ...is that the outside tube of ALL of these heater tubes.....no matter what year or what TYPE......is polyethylene. You dont get special polyethylene just because something is stock or aftermarket. Its not even UHMW......which works for peaks of 275-220F.....and regular polyethylene should not be used for extended periods over 150-175F.......
And.....what does it matter what forum this is?
This problem can and does happen to virtually any ACVW of any type that uses insulated heater tubes.....and its caused by numerous problems.....and not just because someone used stock versus aftermarket parts. Ray |
|
| Back to top |
|
|
Wildthings
Samba Member
Joined: March 13, 2005
Posts: 50331
|
| Posted: Fri Mar 25, 2016 4:20 pm Post subject: Re: Heater tube issues |
|
|
Well Ray, what Type 4 powered Bay has a gas heater that adds extra heat to the outlet air from the heater boxes before it enters the accordion tubes? None that I am aware of. You may know a lot about Type 4 cars but you are really lacking when it comes to buses. Bus owners don't care squat about D-jet because buses never came with with it and they don't care about the Type 4 heating system because its a different system, it operates differently, and there are few parts of any importance that are the same and can be swapped between the two.
I have been dealing with buses for a long time and have never seen a stock accordion tube melt except when someone clamps the ends down without having an asbestos or silicone cuff in place. I have seen the aftermarket accordion tubes melt and I really don't care much what the reason it, they are junk and shouldn't be used or even sold. It is not like the stock accordion tubes are rare, every bus came with a pair and probably half of the buses that end up in wrecking yards still have a usable pair.
FWIW, just because an ad says something is made from polyethylene or some other specific plastic doesn't mean that is what it is made from. |
|
| Back to top |
|
|
Goodhand77
Samba Member
Joined: August 18, 2013
Posts: 236
Location: Forest Ontario
|
| Posted: Fri Mar 25, 2016 4:36 pm Post subject: Re: Heater tube issues |
|
|
Thank you wildthings
I tried my best to follow everything best I could and outside of inferior product not sure what happened ?
And didn't understand what he ment by gas heaters ?
I have a gas heater to heat rear bus area but couldn't figure out how that could ever effect anything
So glad to hear I'm not crazy and thank you for your years of experience with busses and be willing to share those experiences to us who are just learning 
_________________
my world consists of my three girls , my wife and my daughters
and my 72'S!!!!!
1972 beetle sedan almost original
1972 westfalia current project, and loving it!!! |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21507
Location: Oklahoma City
|
| Posted: Fri Mar 25, 2016 5:51 pm Post subject: Re: Heater tube issues |
|
|
| Wildthings wrote: |
Well Ray, what Type 4 powered Bay has a gas heater that adds extra heat to the outlet air from the heater boxes before it enters the accordion tubes? None that I am aware of. You may know a lot about Type 4 cars but you are really lacking when it comes to buses. Bus owners don't care squat about D-jet because buses never came with with it and they don't care about the Type 4 heating system because its a different system, it operates differently, and there are few parts of any importance that are the same and can be swapped between the two.
I have been dealing with buses for a long time and have never seen a stock accordion tube melt except when someone clamps the ends down without having an asbestos or silicone cuff in place. I have seen the aftermarket accordion tubes melt and I really don't care much what the reason it, they are junk and shouldn't be used or even sold. It is not like the stock accordion tubes are rare, every bus came with a pair and probably half of the buses that end up in wrecking yards still have a usable pair.
FWIW, just because an ad says something is made from polyethylene or some other specific plastic doesn't mean that is what it is made from. |
Who said anything about D-jet?
Also....what ad are you speaking of?.....no mention of an ad in the OP.
No one has to say anthing from any manufacturer about being made of polyethylene. It doesnt have to. You forget plastics are my business....and I work on a wide range of ACVW too.
Its the only flexible plastic they can mold in that shape......for that price.
It's polyethylene by default ......vinyl.....not likely ....not flexible enough in that thickness....polyurethane. ...would have had no issues....but would last about 6 months and 10x the cost.....doubtful. All of these are made of polyethylene.
Yes.....aftermarkets have this problem.....and I listed why. Its not generally a material issue...its an assembly issue. That knowledge can be helpful to those who dont have the option of a junkyard close by.
What you fail to realize.....and part of what YOU are severely lacking in.... is the realization. .....if not the knowledge..... that people with a wide range of ACVW interests....peruse a wide range of forums.
Most especially......when you see threads with GENERIC titles like "HEATER TUBE ISSUES".....non bus people with heater tube questions or issues.....are likely to lurk and read.
Not everything I...or other people post are strictly aimed JUST at this exact issue. And many other people operate this way as well. It can help a,wider range of people who stumble upon this thread with the search feature.
So.....my suggestion. ....is either walk on by.....press the "report" button and have me banned......use the block function so you ront have to read my stuff......or borrow some tools to remove the bug from your ass. Ray |
|
| Back to top |
|
|
Wildthings
Samba Member
Joined: March 13, 2005
Posts: 50331
|
| Posted: Fri Mar 25, 2016 7:53 pm Post subject: Re: Heater tube issues |
|
|
You know Ray, for someone who didn't know that ignition timing specs were given in crankshaft degrees, but instead long believed that they were given in camshaft degrees you sure like coming off as an authority on a lot of stuff you just don't know much about. You can write the most protracted post about something you know little about and have a significant amount of what you write be obviously wrong. I do in general ignore you post because of this, while there is probably something I could learn in many of them, it is way too apt to be hidden amongst erroneous material.
I will admit that I know little about the properties of various plastics, but that doesn't mean that what you post about plastics is always right it just means that I (and many others) don't have enough knowledge to challenge what you say. I will though challenge you that the plastic in the stock accordion tubes and the aftermarket ones are the same stuff. I just find that very unlikely. I have seen old worn stock tubes that have been abused in all kinds of different ways and they didn't melt, while the aftermarket ones seem to melt be default.
As for D-jet I didn't say you mentioned in in this thread, it is just that you have brought it up probably hundreds of times and all it does is serve to confuse people. |
|
| Back to top |
|
|
skills@eurocarsplus
Samba Peckerhead
Joined: January 01, 2007
Posts: 16849
Location: sticksville, ct.
|
| Posted: Fri Mar 25, 2016 8:08 pm Post subject: Re: Heater tube issues |
|
|
I'm going to tap in now. I have nothing to offer other than I am glad to see a thread I had no part in end up a train wreck. for a while there I was beginning to think it was me 
_________________
| gprudenciop wrote: |
my reason for switching to subaru is my german car was turning chinese so i said fuck it and went japanese....... |
| Jake Raby wrote: |
| Thanks for the correction. I used to be a nice guy, then I ruined it by exposing myself to the public. |
| Brian wrote: |
| Also the fact that people are agreeing with Skills, it's a turn of events for samba history |
|
|
| Back to top |
|
|
Wildthings
Samba Member
Joined: March 13, 2005
Posts: 50331
|
| Posted: Fri Mar 25, 2016 8:12 pm Post subject: Re: Heater tube issues |
|
|
| skills@eurocarsplus wrote: |
| I'm going to tap in now. I have nothing to offer other than I am glad to see a thread I had no part in end up a train wreck. for a while there I was beginning to think it was me |
I have been a good little boy for quite a while now. Have to do something every now and then though to make sure old fat Santa doesn't get stuck in my chimney. |
|
| Back to top |
|
|
Hoody
Samba Member
Joined: November 28, 2007
Posts: 1948
|
| Posted: Fri Mar 25, 2016 11:24 pm Post subject: Re: Heater tube issues |
|
|
| If you don't care about the air your breathing in when the heat is on then just buy a set of used accordion tubes and install them. Someone offered the original shells for postage. I can offer 2 sets of Bug silicone cuffs for 20 bucks. The high temp silicone ducting is around 30 bucks. And the mighty mat is not expensive. So like I said earlier if your willing to spend a little cash you will end up with a far superior set up then the original that is easily cleaned. It's your dime though. I think most people would be surprised to see the inside of these if they took them apart. Most are more then likely oil tainted. The insulation looks like shredded rags to me. It's definitely not Fiberglas nor rock wool. I don't even think rock wool was invented then....the short story is that the insulation they used is antiquated, the cage rusts, the piece of white fabric they used to catch oil and dust can't be cleaned without taking it apart. And the asbestos cuffs are not anything I want near my lungs. That being said. I guess it boils down to what is worth to breath untainted heated air? Vw did not have the products we have today. |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21507
Location: Oklahoma City
|
| Posted: Sat Mar 26, 2016 2:10 pm Post subject: Re: Heater tube issues |
|
|
You know what….I’ll take the high road and not hi-jack this thread…which I did not in the first place. But a couple of points…and then I will STFU.
Hoody:
Well put in reference to what you might be breathing.
A quick note: rockwool was made first in the mid 1800’s. Main production started around 1850 in the British steel industry. It generally has smaller air pockets than fiberglass and a higher temperature range by almost double.
The smaller, tighter stranding makes it simultaneously an insulator because it does have some air entrained….but makes it a better barrier against heat LOSS....so it works well for these heater tubes because it keeps more of the heat inside the tube.
You don’t see it much anymore….because it’s under investigation as being carcinogenic in the same effect as asbestos in the lungs…which is why aftermarket tubes most likely do not use it.
A couple of pictures of what Hoody and others have pointed out of the construction of a stock heater hose.
The Rock wool casing
The steel endcap crimped to the galvanized chicken wire with the asbestos gasket on the left.
The whole mess.
By the way….you can encapsulate the inside of the rockool with a high temp spray paint and you will no longer breathe the oil or fibers. A bit tricky to apply as you have to peel off the rockwool and then re-install it.
How would I know from pictures that the melted hose is polyethylene:
For the record:
Because I work with plastics, rubber, elastomers, metals, glass, chemicals daily….across about 15 major industries and about 10 more sub industries that manufacture products and parts of all types by many processes......
One of the dirty but interesting tasks I have to do..…on an almost weekly basis…is identifying the plastics and rubber materials for many of my clients who want to copy or reproduce a part or product and only have a sample scrap.
I have to clean the plastic, which may involve chemicals, detergents or abrading to get to uncontaminated plastic and then do a plastic burn test to get a close idea of the family and type of plastic.
Smoke color and type, soot production flame progression, melt pattern, sparking, odor and flame color are taken into account.
Here is a good basic explanation of this process…but not the preparation for it
http://www.boedeker.com/burntest.htm
I can tell you from the photo....that tube is polyethylene. |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21507
Location: Oklahoma City
|
| Posted: Sat Mar 26, 2016 4:14 pm Post subject: Re: Heater tube issues |
|
|
Wow....thats really crappy. A measured accurate response......and my last post gets edited by a heavy handed moderator.
Very poor behavior! Ray |
|
| Back to top |
|
|
Wildthings
Samba Member
Joined: March 13, 2005
Posts: 50331
|
| Posted: Sat Mar 26, 2016 6:47 pm Post subject: Re: Heater tube issues |
|
|
Ray,
You have posted about D-jet on the Bay Window forum in about 6% of your post, and of all the D-jet posts in the Bay Window forum you account for right at a third, ~34%.
You have posted on D-jet 191 on the Bay Window forum 191 times as of now.
http://www.thesamba.com/vw/forum/search.php?search..._chars=200
In total you have 3303 posts on the Bay Window forum of which about 6% mention D-jet
http://www.thesamba.com/vw/forum/search.php?search..._chars=200
In total there are 559 posts on D-jet in the forum, a third of which are yours.
http://www.thesamba.com/vw/forum/search.php?search..._chars=200
Yes you did give someone advise claiming a normally functioning distributor had something like ~80° of crankshaft advance when timed normally, claiming that distributors specs where in camshaft degrees.
Yes I have mentioned D-jet fairly often myself as about 0.25% of my post mention D*jet |
|
| Back to top |
|
|
scrivyscriv
Samba Electrician
Joined: October 04, 2011
Posts: 2922
Location: Memphis
|
| Posted: Sat Mar 26, 2016 7:38 pm Post subject: Re: Heater tube issues |
|
|
| aerosurfer wrote: |
Interesting you are using my picture as your own album.... the full shot from under my bus.
(pic) |
that's the reason 95% of what I upload to the samba gets a copyright watermark with my name over it!
_________________
Robert in Memphis
Dünkelgrügen 1967 Java Green bug thread
Engine rebuild thread
If you're ever in the Memphis area, you are welcome to stop by for advice and help. |
|
| Back to top |
|
|
airschooled
Air-Schooled
Joined: April 04, 2012
Posts: 12716
Location: on a bike ride somewhere
|
| Posted: Sat Mar 26, 2016 7:43 pm Post subject: Re: Heater tube issues |
|
|
| scrivyscriv wrote: |
| aerosurfer wrote: |
Interesting you are using my picture as your own album.... the full shot from under my bus.
(pic) |
that's the reason 95% of what I upload to the samba gets a copyright watermark with my name over it! |
Yeah but 95% of the samba also posts crappy cell phone pictures. You're in a minority in that you actually know how to use a camera. 
_________________
Learn how your vintage VW works. And why it doesn't!
One-on-one tech help for your Volkswagen:
www.airschooled.com |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21507
Location: Oklahoma City
|
| Posted: Sat Mar 26, 2016 8:58 pm Post subject: Re: Heater tube issues |
|
|
And again....what is your point....as I didnt mention it at all.....in this thread. You did.
Also.....as was noted and posted ....before our illustrious mod happily deleted it for me......virtually all of my D-jet mentions were technically relevant to the conversations they were in......whether you were personally interested or not.
And....everything I have posted in this thread so far
....is heater duct related.
So.....I just assume yo either have a personal ax to grind......or your just an as*hole.....you can choose. No difference to me. Ray |
|
| Back to top |
|
|
Wildthings
Samba Member
Joined: March 13, 2005
Posts: 50331
|
| Posted: Sat Mar 26, 2016 9:16 pm Post subject: Re: Heater tube issues |
|
|
| raygreenwood wrote: |
And....everything I have posted in this thread so far
....is heater duct related.
So.....I just assume yo either have a personal ax to grind......or your just an as*hole.....you can choose. No difference to me. Ray |
And a lot of what you posted in this thread was dead wrong, buses don't have inline gas heaters as do Type 4 cars, but you apparently don't know that. Your post would not even have been correct had it been for a Type 4 car instead of a bus it was so far off. My ax to grind is that you post a pile of erroneous and sometimes just plain irrelevant information maybe in an attempt to impress people and that most of the time when you mention D-jet it is totally unnecessary and is just going to confuse someone who doesn't know that very little about D-jet applies to an L-jet fueled Type 4 engine.
I don't know how many people have posted to the Bay forum over the years but I would guess that less than 0.1% of them have posted about D-jet because it just isn't relevant to a Bay. |
|
| Back to top |
|
|
Goodhand77
Samba Member
Joined: August 18, 2013
Posts: 236
Location: Forest Ontario
|
| Posted: Mon Mar 28, 2016 3:55 am Post subject: Re: Heater tube issues |
|
|
Well guys sorry for opening the door for such an issue to begin
But moving on I don't have any gas heaters added that effect manifold heat ....
Just regular type 4 set up
Anyways I currently do not have a set of tubes to use since mine died , and don't have the coin or time "right " now to rebuild and aquire the needed stuff
So for $18 and stuff in my garage not sure why people are not doing this ?
Maybe I will find out the hard way 
But upon realizing when someone mentioned what I'm breathing in ? Why does the insulation of any type go on the inside of tube ? Why is it designed this way? Makes sense to me to use straight pipe and wrap the outside ....
This is how I did the main long centre tube to front of bus , so why not in place of accordin tubes ?
No more breathing in Fiberglas of any type
So not sure if I should rebuild original ?
Unless I'm trying to make "original", which my bus isn't ...
Had to put on electric fuel pump on side of road when bus died on road trip due to mechanical fuel pump failure ....
So here is acouple photos of my solution yesterday , super easy and didn't need to fabricate anything on the bus to make this work so fingers crossed it works out with no surprises but atleast I will feel better about air I'm breathing in , can't believe I never thought about this before ?
_________________
my world consists of my three girls , my wife and my daughters
and my 72'S!!!!!
1972 beetle sedan almost original
1972 westfalia current project, and loving it!!! |
|
| Back to top |
|
|
zerothehero
Samba Member
Joined: March 16, 2008
Posts: 214
Location: Derbyshire
|
| Posted: Mon Mar 28, 2016 5:04 am Post subject: Re: Heater tube issues |
|
|
I may be wrong but I think the design of the original tubes with insulation on the inside served also to absorb some of the engine noise.
The replacements you have fitted look good
_________________
I like caves..
Caves are cool
-------------------
1979 Devon Moonraker 1600 twin port
1978 Oz Microbus 2000 FI Auto |
|
| Back to top |
|
|
busdaddy
Samba Member
Joined: February 12, 2004
Posts: 51112
Location: Surrey B.C. Canada, but thinking of Ukraine
|
| Posted: Mon Mar 28, 2016 8:02 am Post subject: Re: Heater tube issues |
|
|
That looks good, but as mentioned the OG accordians were mufflers and you will hear a little valve train and fan noise through the heater now, not a big inconvenience compared to freezing your ass off
_________________
Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
|
| Back to top |
|
|
scrivyscriv
Samba Electrician
Joined: October 04, 2011
Posts: 2922
Location: Memphis
|
| Posted: Mon Mar 28, 2016 8:38 am Post subject: Re: Heater tube issues |
|
|
Valve train noise... Easy to hear that exhaust valve right before it drops 
_________________
Robert in Memphis
Dünkelgrügen 1967 Java Green bug thread
Engine rebuild thread
If you're ever in the Memphis area, you are welcome to stop by for advice and help. |
|
| Back to top |
|
|
|
