Temperature of the exhaust of model engine

[xander janssen]

Due to a design challenge, I cannot silversolder/braze a part in the exhaust.

Any ideas on how hot the exhaust manifold of a low revving model engine like a Webster engine gets?

Maybe I can soft solder or glue it with high temperature (250 degree Celcius / 482 degree Fahrenheid) silicone. It only needs to seal as the parts are held in place mechanically by other means.

Regards,

Xander

 

[minh-thanh]

Xander !
Post design picture of the position of the exhaust and the exhaust pipe , it's easy for everyone to comment

 

[Roger B]

A quick show and tell. This is my 25cc 4 stroke running at a moderate speed off load. There is some uncertainty about the emission factor for IR temperature measurements. I also made measurements with a contact probe (but didn't have enough hands to take pictures) which were around 300°C. This engine is different in most ways from yours but may give a data point.

 

[Nerd1000]

My Webster's exhaust easily melted the soft solder I first used when making a muffler for it (I can braze, but didn't want to burn the steel wool I packed inside). Top of the muffler popped right off. I brazed it and accepted not having any packing.

If you can't braze or weld I suggest assembly by press fit.

 

[Steamchick]

Silicon or Viton O-rings can work up to around 300C,,, and an exhaust pipe at the head exhaust port can get that hot! So a bit of suck-it and see? "plumber's lead" is a sealing compound for water systems that sets rock-hard ... (You REALLY want to avoid lead!!), exhaust paste for cars the same, but sticks well - I use it for making sealing ceramic burners, steam boiler cladding, etc. Anywhere HOT that needs a paste type seal. Comes in cheap small tubes or industrial cartridges! Silicon sealant is flexible but chars at exposed flame zones. Glass fibre twisted into "string" is quite good in some applications, especially where clamped to support it against back-pressure, like with a gland-nut. (NEVER use ASBESTOS! It is illegal and has been banned!). PTFE tape can take around 300C. But does not melt, it simply ablates (vapourises directly from solid). It can give off TOXIC Flouride fumes (OK for returning space capsules 100miles up, but not OK in your workshop, where you breath!).
Be careful, use "Car exhaust assembly paste" - but wear gloves as something nasty chemical resides in this stuff as well.
K2

 

[Steamchick]

You could try a Zinc fluxed soldering rod...? Good to nearly 400C? works with steel, copper, brass, etc? Check a proper supplier to get the rod with the correct alloy blend for you material application. "Aluminium repair" rods are not the best for copper, but will work... (I use them to make aluminium "boxes") Each base material combination prefers a different alloy, not just the cheapest!
K2

 

[bluejets]

Blue tip silver solder, cadmium bearing the best if you can track some down.

 

[a41capt]

Believe it or not, JB Weld held as a repair on a 351 Ford exhaust manifold for years without failing. Not sure what others have found, but that repair lasted well beyond my selling of the truck. On the order of at least 12 years until I lost track of it!

John W

 

[Steamchick]

Bluejets, please note Cadmium is highly toxic, which is why it is a banned substance in most Western countries. (E.G. UK). Please recommend safe products or advise of risks, when using this website, as otherwise an innocent reader could get hurt if they use it. (Industry cannot use Cadmium now!). I don't know the details of its toxicity, so cannot explain.

 

[bluejets]

I don't know the details of its toxicity, so cannot explain.

Well why comment.?
Used it for 50 years with no problem...trouble is greenies tend to get involved in many things they don't understand and make it impossible at times over a drop in the ocean.
I notice many that get mains connection advice from diluties in here and other places, yet none get the boot there.
I'd say, if you don't like it, fine,don't use it and stop poo pooing those that do.

 

[Charles Lamont]

Well why comment.?
Used it for 50 years with no problem...trouble is greenies tend to get involved in many things they don't understand and make it impossible at times over a drop in the ocean.
I notice many that get mains connection advice from diluties in here and other places, yet none get the boot there.
I'd say, if you don't like it, fine,don't use it and stop poo pooing those that do.

A bit of an overreaction, perhaps?

 

[Bentwings]

A bit of an overreaction, perhaps?

I’ve refused to weld any galvanized products it’s a real health hazard some much worse than others at 80+ I still test 98% blood oxygen atvthe doc office and at home a simple device slips on finger test blood oxygen and pulse I use it everyday it’s limitation is cold hands in the winter the infra red apparently doesn’t work as well I just wash hands in warm or hot water then it works fine my late so passed away from idiopathic fibrosis. He worked for years in smoke filled casino then use plenty of auto pains using iso cyanates in Gardner without paint masks . No doubt some ofvthe cause of illness .

I used to measure model exhaust and learned a long time ago there just aren’t soft solders that hold up at 900 deg F Copper TIG welds very nicely but get very hot every quickly inusual use heat sinks it also brazed well with silicone bronze I’ve us what AC repair guys use it usually flux less I asked the question a while back I only clean copper well then weld or braze quickly it gets pretty soft if you cool I water and black scale can wear again I just clea it off I don’t really like glass bed cleaning maybe crushed walnuts works I have not tried that fo models I trim excess copper flanges and use accurate scale to achieve total weight reduction

 

[william_b_noble]

Silver solder which jewelers use of cheap, easy to use, and flows at temperatures easily reached by propane torches. You may want to consider that, and it's not toxic and easy to get, including in a paste form mixed with flux. 1600 t9 2900 deg f

 

[peterl95124]

Well why comment.?
Used it for 50 years with no problem...trouble is greenies tend to get involved in many things they don't understand and make it impossible at times over a drop in the ocean.
I notice many that get mains connection advice from diluties in here and other places, yet none get the boot there.
I'd say, if you don't like it, fine,don't use it and stop poo pooing those that do.

yes, anecdotally there are lots and lots of people that smoked all their lives and didn't get cancer, but statistically its still not a good idea to smoke, ditto with using cadmium, ditto with using thoriated tungsten, there's no need to use these things and no need to advise people that its OK for them to use just because you got away with it.

 

[rick9345]

yes, anecdotally there are lots and lots of people that smoked all their lives and didn't get cancer, but statistically its still not a good idea to smoke, ditto with using cadmium, ditto with using thoriated tungsten, there's no need to use these things and no need to advise people that its OK for them to use just because you got away with it.

Smoked since12 I'm 77 mechanic,machinist, been around carcinogens all my life,Doc says I'm very unusual, just be careful follow precautions, but enjoy life ,its not ok do my type of misspent youth,just don't hide under a blanket of being afraid. Can't get to heaven till you Die anyway.

 

[Steamchick]

Yeah, I hear you. Stop bleating and just respect the laws that some substances are BANNED BY LAW in namby-pamby soft headed countries like UK, Germany and USA, but not "toughies" like some African countries, China, North Korea, and Russia...
Just don't tell the website to use illegal substances. - At least without a Health warning - like they do on Cigarettes.
I ride a motorcycle. Almost nothing is a fatal as that hobby, but I don't recommend it to anyone as I have read the (secret) statistics on fatalities compared to smoking, guns, knives, etc.. But smoking and motorcycling are not (yet) totally banned anywhere as far as I know... (some guns and knives are in the UK).
- I am not even going to argue when the Government say something is banned because of health risks.... Just please don't try and tell us you know better than "Experts" - sorry, I meant the lawmakers... It is simply unprofessional. Just advise the health risks for those that can use whatever you suggest.
Have you seen the precautions taken by the contractors who come and remove asbestos from your house? ABC suits! - They have to follow the law!
Nuff said.
(Moderator, if my reaction is not appropriate, please just delete it. I am simply annoyed that some people do not respect the laws of some countries, when it comes to health and safety warnings.)
K2

 

[peterl95124]

just don't hide under a blanket of being afraid. Can't get to heaven till you Die anyway.

sorry, I thought the purpose of this forum was to share useful information, my mistake...

 

[minh-thanh]

Hi All !

I don't know if the above materials are toxic or not.....and I don't intend to use it so I didn't look online about it.
About cigarettes : We shouldn't discuss it because that's not why we're here.

(Moderator, if my reaction is not appropriate, please just delete it. I am simply annoyed that some people do not respect the laws of some countries, when it comes to health and safety warnings.)
K2

I understand ,,...but don't go too far

We are here to have fun and learn what we don't know ... to make us more knowledgeable .
Simply : Calm down, Sit down, listen and think ! ....

 

[Bentwings]

Smoked since12 I'm 77 mechanic,machinist, been around carcinogens all my life,Doc says I'm very unusual, just be careful follow precautions, but enjoy life ,its not ok do my type of misspent youth,just don't hide under a blanket of being afraid. Can't get to heaven till you Die anyway.

I look at it this way you are a bomber making a bomb run cancer are the fighter lurking around ready to shoot you down flak is the cance bugs being shot at you . When your number is up there is not much you can do but stay in formation and pray their aim is off. I got hit but so far made it home Now riding in medi vac to remission . It’s tough measuring remaining lifespan in hours. It’s like getting hit with 20 mm cannon fire. The big tough bomber can’t take many of those . Now for the next 6weeks I get hit with a 200mm long needle in tummy at the cancer repair shop . When this is done my tour will be about over. I’ll be able maybe to go on the sales tour

Thanks to all who served

Byron

 

[master53yoda]

I work with youth quite a bit in and around my foundry I talk about safety when pouring , one of my things is footwear that is leather, and no laces. ( i do mostly aluminum) That said there are those that wear sandals, tennis shoes etc. they may gainsay the the need for functional foot wear, at least until they have a crucible failure. I tell them that they can believe that you can put your hand in boiling water all they want, but it doesn't change the fact that if skin is exposed to that temperature long enough it will burn it. I avoid the things statistics show that damage is "probable." We are all genetically different and have different levels of immunity to some things but live is a little like playing Russian roulette when we try to gainsay commonsense.

ART b