The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: Terryb on 27.06. 2017 16:18
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Has anybody used Tapox on an Oil Tank, not to resist ethanol, but as a sealant?
May be a silly question!
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Has anybody used Tapox on an Oil Tank, not to resist ethanol, but as a sealant?
I've never heard of it but their marketing looks optimistic. Could you be sure to properly degrease an oil tank?
I once, (circa 1966) worked in a plating works; there was a tank that held a vapour that condensed on metals and thoroughly degreased them. I used to know what the vapour was; maybe it was Carbon Tetrachloride? Probably illegal in First World countries now.
Update: I believe it was trichloroethylene
Yikes! https://en.wikipedia.org/wiki/Trichloroethylene
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Trich Tanks.
Most engineering shops had them in the 60s and 70s, they were used for degreasing components, the parts were put into a wire basket and into the tank to cook for a few minutes.
The fumes were very strong and made your eyes water.
They were great for bike parts, especially chains, had many a bolicking for using them for foreigners.
Having a bike and working in engineering was a real help, everything from machining to plating and painting happy days.
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After reading that Wikipedia article I've discovered how dangerous that stuff is.
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hi guys, yes Carbon Tetrachloride was used as a degreaser, we used it to in the 70ties to degrease pipe threads before a sealant (expando) was used on gas pipes. Also it was used in offices for cleaning printers now banned because it was very dangerous if fumes were inhaled, cheers
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Hi All, thanks for the advice.
The reason for asking was that I am just preparing the petrol tank for Tapox, which I've used before with success. I have a very small leak (not easily detectable, less than a pin prick size) in the oil tank in the top third. But low enough to be below the oil level and as I will have excess Tapox left over from the petrol tank I thought of using it on the oil tank and hopefully seal the leak.
I've cleaned and degreased the oil tank and then treated it with Fertan, I've now flushed the oil tank through to remove any excess and now waiting for it to dry. If you've ever used Fertan it leaves like a black charcoal type film inside the tank, which when dry helps the Tapox to key to the surface. So now I either have to continue with the Tapox process or find a way of cleaning the Fertan from the inside, hence the post.
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I asked the forum about sealing my oil tank that also had a small leak; the consensus was a no because of the risk of liner coming off and blocking oil flow. Lining a petrol tank is not so risky. I bought another oil tank.
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I would agree about not using a plastic type tank liner on a oil tank (bag) as many people experience adhesion issues. However small leaks are easily corrected. I am a big fan of high tech welding, and while I am only at best a marginally skilled welder, I worked with some of the best welders in the US and still access many of them who are willing to do small jobs on the side. Cannot beat a skilled TIG welder using the best materials. And fabbing a new tank, thats what I would do.
But repairing a vintage and well worn & seasoned,,,,,,,and by seasoned I mean metal fatigue. I would braze it. Some oil tanks are either silver soldered or brazed in initial construction as well so, examine joints, fittings and seams carefully. But good old school brazing on a properly cleaned surface will do the job just fine. Follow it with a leak test. (Warm the tank to oil operating temps and then add water or petrol and look for a leak, (Be careful that the liquid is also near same temp) I would avoid pressure testing.. If still signs of a leak easy to clean and prep again.
Silver solder is also a viable method but less common. Olden days some metal workers and body shops used lead, but not a easy skill to learn and not suitable for joints and sealing surfaces.
As to all these drastic chemicals, thats a bit over kill. Find a radiator shop or commercial stripping shop and have the oil bag dipped. I use a commercial shop down in the city industrial district and oil bags are $20 each to have chemically stripped. If you want to clean and strip it yourself,, paint stripper and then clean with MEK or just use plain old Lacquer thinner from a body shop supply store. (Lacquer thinner is not used anymore for paint but still sold for cleaning parts or cleaning paint equipment). If you want the next level of chemical clean then buy some brake cleaner solvent in a aerosol can. It will clean the last remnants of oils away and drys quicky with no residue. (Did somebody say "Earth day"???)
Trichlor is an awesome solvent and lubricant. But highly cancer causing and very dangerous. I used to LOVE using it for a cutting lube. When cutting or grinding on stainless or high grade steels when used a cutting lube the carbide tooling slices thru and removes metal like its butter.
This is because of its unique properties. Skin, when exposed to it will get frostbite. There was a few very stupid employees I used to work with, who huffed it. Squirted it inside a container and used it as an inhalant. I bet they are all dead now,., they were pretty low functioning to begin with. Ironically, one was employee of the year because he had perfect attendance in 10 years of employment.
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Thanks guy's, I think I had already decided that Tapox is not for oil tanks. Thanks for the input though, firstly I need to locate the hole and then decide how to seal it. possibly braze it I think. Thanks anyway.
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Even good old bar solder would do the job and is simple to apply. It certainly worked for my Velo petrol tank once the failed tank liner was removed.
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Mmmm...Yes, Carbon Tetrachloride! During my apprenticeship in a steel works in the 60's, we used buckets of CT to soak burners caked in baked on heavy fuel oil, it was the only degreaser that would clean them - even used rags dipped in the stuff to clean oil from our hands...Hell, I hope to have a few more years of biking then.....But, the workshop was a great place for the "homers" - there were even trailers made and towed out past security at the end of nightshifts without them realising.....
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Oh yea, we used to make the hydraulic tubes for JCB and Caterpillar and the tube was degreased in baths of it prior to welding but they had a covering seal of table tennis balls floating to stop it evaporating and us sniffing it *smile*
A mate of mine used to repair such as that with a small gas torch and stick solder, bakers fluid flux on it first and during the soldering, watched him do many a truck radiator , vintage car ones in brass or copper and my petrol tanks, would even cut a bit of tin from a bean can and solder the patch on in the lunchbreak if we were stuck..........such an art that I never got the hang of *conf*
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Has anybody used Tapox on an Oil Tank, not to resist ethanol, but as a sealant?
I've never heard of it but their marketing looks optimistic. Could you be sure to properly degrease an oil tank?
I once, (circa 1966) worked in a plating works; there was a tank that held a vapour that condensed on metals and thoroughly degreased them. I used to know what the vapour was; maybe it was Carbon Tetrachloride? Probably illegal in First World countries now.
Update: I believe it was trichloroethylene
Yikes! https://en.wikipedia.org/wiki/Trichloroethylene
Yep,
Trico the only stuff that degreases spotlessly at room temperature with no loss to the atmosphere.
Benzene is better but it is very had to capture the vapour
Trico got banned because it is fatal if inhaled through a cigarette .
And of course it is one of those evil clorinated hydocarbons that was burning a hole in the ozone layer or would if it ever got that high which it can't but to undrstand that you would have to have done some physics past grade 2 ( 14 year olds ) which no beaurocrats seem to have done.
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Solder is the way to go.
Tinmans solder , not electrical solder .
Best stuff is about 30% tin and has a little copper & iron in it.
Next best is a plain old steel weld.
Oxy is the way to go, a piece of doggy dune it and use some fine wire .
Oddly enough uncoated MIG wire works really well with OXY .
Bronze is never a good idea on anything that vibrates and it is really more of a glue than a hole filler
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MIG wire also works great as filler rod for TIG welding also.
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" Bronze is never a good idea on anything that vibrates and it is really more of a glue than a hole filler"
Trevor, I am curious about your statement above,, (I am not arguing just asking for clarification)
As I have seen a LOT of gas and oil tanks with brazing on them, and in many cases many oil pipes and fuel lines seem to have been sweated together using brazing as well. I have a vintage Triumph frame that was in an unfortunate fire many years ago sitting here as well, and the owner wants to restore it. I did some testing and the metal is not excessively cooked but we plan to install the frame in a jig, check for straightness and re-braze all the joints and casting lugs.
I have some old printed articles here and they state that the factory for BSA & Triumph used a hearth system to build the frames and the castings were heated up in heath furnace and then the plain steel frame tubes were inserted with flux and brazing. This is clearly visible on many frames when stripped. I follow some metal fab and industrial engineering forums and tech (always trying to learn) and much discussion on such over the years... Some speciality builders are using Brazing as a signature artform method as well... for example check out this beauty.
(See Pix).
If I am off the mark here, feel free to correct me.
(Known as "Weld-nrop" some fetishists find such craftsmanship stimulating)
See : http://www.blogofthebiker.com/2016/09/bare-minimum-brazed-frame-gsxr-racer.html
More on topic, a Japenese custom shops version of a BSA A7 Plunger bike using a lot of Brazing
See: http://sgrallying.blogspot.com/2014/06/cyclops-bsa-a7-plate-armor-bobber.html
*NOTE* I find it amusing that certain words are auto-edited on here,, funny that! And on certain forums when discussing Machine shop P R O N, Crankshaft P R O N, or Welding P R O N we spell it that way to avoid spam filters and email issues.. So much for "Taking the P**"
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"Bronze is never a good idea on anything that vibrates and it is really more of a glue than a hole filler"...
Wouldn't the same apply to tinmans solder?
- I've had good results with both brazing and silver solder.
If the hole is anything bigger than a pinhole I cut little copper patches and silver solder them over the hole.
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Brazing is an excellent means of joining metals. Tinman's solder has its uses too. Look what happens if you send an early petrol tank off for powder coating. The oven melts the solder and you get back a small pile of bits of carefully shaped sheet metal. I like tinman's solder for fixing small leaks as it's simple for the home handyman without the skills or equipment for welding or brazing to use. And you aren't going to destroy the tank you are trying to fix as can happen with unskilled attempts to weld.
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It would be a shame to paint that frame sluggo its a real work of art.
Had a mate in the 70,s who built and raced sidecar outfits and many in the paddock including his were all brazed and some crashed with no failed welds. I remember as an apprentice being told that if done correctly brazing was as strong as the parent metal.....don't know if that's correct or not *conf*
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There are blokes on here much more qualified to comment on this but... Brazing was used for lug/tube assemblies of course but, also for steel tube frames where welding would compromise structural integrity of the particular alloy steel of the tubing (Bluddy'ell that's a mind boggling concept, let alone the lingo!)
But those pics of the brazed joints (Sluggos) makes me feel err... queezy! Yes the braze joints are beautifully executed, But...
WTF? All that's surplus to requirements surely? Why not design and fabricate the frame so there are continuous but overlapping tube elements rather than cutting, and putting in all those little fillets etc. Surely that's the way to structural madness!!!
(- Just saying! imagine the improvement in structural integrity if those tubes were continuous, overlapping and brazed, instead of cut, shut, and brazed. Every cut joint is concentrating and magnifying the destructive forces.)
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If you are repairing cast iron, brazing is absolutely the way to go. Nirod welding does nothing but ruin future attempts to repair.
The same way brazing does. If you have ever tried to weld something that was previously brazed you know what I mean. The metal that was brazed is contaminated with bronze, the weld just spits back at you. Lead does the same thing.
So basically, once you lead or braze a repair, you are stuck trying the same method again and again even if it fails. Or making the original problem much worse by having to cut all the contaminated metal out. So a pinhole is now the size of a quarter etc.
I believe brazing was an inexpensive and quick production assembly method. Once mig welding became economically viable, brazing was quickly replaced by a faster, stronger method. It did not hurt that someone could be taught to mig weld in minutes either.
Lee
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A weld a braze a solder blob are all castings.
Metal melted onto a place and allowed to solidify.
The only difference between brazing & a casting is the absence of a mold.
SO the ultimate strength of the joint comes down to the strength of the alloy.
A brazed joint is always a lap type of joint between two very close fitting parts and the strength of the joint is determined by the amount of overlap.
So you have a forged frame lug with a machined hole into which goes 1/2 ( or more ) of tube.
A highly reducing flux is melted into the joint (usually borax based ) then metal is melted in and flows under capillary action to fill the void.
There is a tiny amount of penetration of the filler rod into the base metal but the phases formed are quite brittle and the braise metal is also quite brittle.
Some high alloy steels can not be welded because the heat causes phase changes or grain growth in thin sections.
Nearly all braisings fail through the filler metal.
I do not know what alloy your mates frame is made out of nor the alloy used to weld it but fillet brazing, some times called bronze welding is not particularly strong and has a very low fatigue strength.
The deposits themselves look nice, very neat & uniform but have been done too cold and in too big a step.
If a student presented that to me he would be failed.
" Bronze is never a good idea on anything that vibrates and it is really more of a glue than a hole filler"
Trevor, I am curious about your statement above,, (I am not arguing just asking for clarification)
As I have seen a LOT of gas and oil tanks with brazing on them, and in many cases many oil pipes and fuel lines seem to have been sweated together using brazing as well. I have a vintage Triumph frame that was in an unfortunate fire many years ago sitting here as well, and the owner wants to restore it. I did some testing and the metal is not excessively cooked but we plan to install the frame in a jig, check for straightness and re-braze all the joints and casting lugs.
I have some old printed articles here and they state that the factory for BSA & Triumph used a hearth system to build the frames and the castings were heated up in heath furnace and then the plain steel frame tubes were inserted with flux and brazing. This is clearly visible on many frames when stripped. I follow some metal fab and industrial engineering forums and tech (always trying to learn) and much discussion on such over the years... Some speciality builders are using Brazing as a signature artform method as well... for example check out this beauty.
(See Pix).
If I am off the mark here, feel free to correct me.
(Known as "Weld-nrop" some fetishists find such craftsmanship stimulating)
See : http://www.blogofthebiker.com/2016/09/bare-minimum-brazed-frame-gsxr-racer.html
More on topic, a Japenese custom shops version of a BSA A7 Plunger bike using a lot of Brazing
See: http://sgrallying.blogspot.com/2014/06/cyclops-bsa-a7-plate-armor-bobber.html
*NOTE* I find it amusing that certain words are auto-edited on here,, funny that! And on certain forums when discussing Machine shop P R O N, Crankshaft P R O N, or Welding P R O N we spell it that way to avoid spam filters and email issues.. So much for "Taking the P**"
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Hi All
It seems to me that people here are confusing brazing and bronze welding *????*
Lugs and tubes are brazed using brass filler
The racing frames "Harris" and the like are bronze welded, using a silicon bronze filler rod
John
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A bronze weld is just a braize with a stronger filler metal.
THe bronze does not alloy with the tube to form a join with consistant metallurgy from the HAZ through the "weld" to the opposite HAZ
The parent metal is not melted into the filler rod, the 2 remain totally seterate entities with the exception of some solid state diffusion .
It never was and never will be anywhere near as strong as a real steel weld.
Race frames in particular were only designed to do a single season and they still crack through the middle of the filler metal.
I have some race frames in the shed and they all have cracks in the joints.
Some are worse than others.
The problem is some one makes or designs a frame in plain 04 carbon steel tube then some one else copies it in light weight alloy tube but does not design the joints properly for "bronze welding" and expects the bronze to exhibit the same strength as a steel weld which of course it can not because it is still nothing more than a copper based alloy casting.
A welded frame can have members in tensin where as a brazed ( brass or bronze ) frame must have all members in compression so all the filler rod is actually doing is holding the parts in place which is why you see one tube wrapping around another then held in place with the rod.
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I must say, this forum is very educational!