Just to add a passage on the internet I found:

“Bonderized steel is actually galvanized steel that has also gone through a phosphate bath. This bath acts as an insulator between the galvanized zinc creating an ideal surface to paint on. It is no wonder why this form also has the nickname “Paint Grip.” This is a material that must be painted on in order to reap the long lasting benefits. When it is left unpainted, it opens up a world of problems. White rust, scratch marks, and more can damage the material since it is technically unfinished. Unlike galvanized steel, bonderized does require further work, it can’t just be put up and left. Any project that is in an area that experiences heavy rainfall or humidity should be using bonderized steel instead of galvanized. The extra coating and paint will help it to withstand the elements”.

Advert Cycling manual 1947

[QUOTE=unworthy1;23472260] What other builders used such Bonderizing, BITD?QUOTE]

I've seen the "Bonderized" decal at the top-front of the seat tube on some bikes, and I'll try to find some. The 50's and 60's Grubbs and Claud Butlers (from Holdsworth) had this "special process" sticker. Probably Bonderizing under another name for legal reasons. AWAC, does your European have one of these?
I would like one for my 1959 Coureur.

[QUOTE=1989Pre;23472796]No sadly I have no transfers on the European. Although it came with a nicely hand painted club and rider name, Paul Newman.

But just looked and H Lloyd have them.
https://hlloydcycles.com/pages/searc...e?q=bonderised

The Pyrene company

https://en.wikipedia.org/wiki/The_Pyrene_Company_Limited

https://en.wikipedia.org/wiki/Phosphate_conversion_coating#Parkerizing

interesting that "Parkerizing" is also mentioned, which some of us might know as the dull dark (non-reflective) finish that Ka-Bar knives had which provided rust-resistance as well as (maybe) "stealth" for Marine Corps in hand-to-hand combat.
But I digress...from what little i know that (Parkerizing) is basically just the phosphate bath portion of the Bonderizing process, minus any galvanizing zinc, but followed with a baking which maybe allows for a thicker coating than if just dipped and dried(?)

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reportedly 1972 example just posted over at RetroBike forum -

​​​​​​https://www.retrobike.co.uk/threads/...pecial.4913669


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Interesting frame for sale on ebay UK at the moment from Pedalpedlar. Serial number 2564. The last recorded was 2401, but as noted earlier the frame builders done a few in retirement. If I find any advertised with serial # visible I will add them until I can get time to do a spreadsheet.



Allin seen on ebay 2564

Allin seen on ebay 2565

Allin seen on ebay serial 2564

Ok Sulphamic test day.

I was going for ;
1 cup=236ml.
2360ml=0.51 gallon
1:10 strength mix.

But that was too scientific so went with;

1 cup/236ml to 15lt of cold water (now sitting in the sun of 24c today). I will use the measure of cup/litre to help with your measures if you try it, get the cup-measure spoon from a home baking store in the UK or US.

Made up the bucket of bi-carb at twice the strength, 2 x cups to 15lt to act as a dip and acid neutraliser, make this first as a wash if you need it! Don’t forget gloves and eye protection etc.

If it is too weak I can add more. Looking for a mixture I can leave overnight 12-24hr that does not harm paint or decals and takes rust off. I like to drop something in a bucket and do something else and not stand watching it, more of my life to go around…..lol.

Fork was chosen because it’s bent, it has I think factory blue underneath what looks like a rattle-can black top coat with slight rust on the stem. If it takes bad prep paint off but leaves factory paint, well that would be a holy grail bonus! Forks not fully submerged so I can see if any fading occurs when they are pulled out.

Stem is chrome steel with a steel wedge, not aluminium. I expect it will be too weak, but you never know…..



Test subjects

In we go

Hole cut outs for fork

The measuring cup!

Rusty stem

good luck! that's a nice looking stem, too, what brand izzit (if you know)?
My guess based on less-carefully measured acid baths is the rust will come off (but after you also wipe the parts off with a rough cloth) but usually paint stays put (even crap quality paint) UNless the paint was on top of rust, in which case it ALL will be removed (as will chrome) with that rust.
YMMV
Oh and since that stem has a brazed seam, maybe try to minimize time that it steeps in the acid, just in case this Sulphamic stuff attacks the bronze

Not sure of the stem make yet. Will pop a photo on, if you have ideas let me know. I have a feeling the acid will not do too much, but who knows! Lunch tomorrow is 24hrs of a soak, if nothing, then in goes a another cup!

It s a very valid point re the braze but if it attacks the braze then let it be so on the stem rather than the lugs, at least we will know!



Photo of the rusty stem

Ok Scotty, take it to warp speed 2 cup.

It had over 24hr started to work, but rust not completely removed so I have now a second put cup into the original mix. If that works quicker I will find something else rusty (which I have plenty of….) and prove the speed of removal.

Interesting some black rattle-can flakes in the water. Was that just loose, or where some rust had sat underneath. The factory blue does not seem affected.



24hr 1 cup in 15lt

24hr 1 cup in 15lt

Why don't you just sand that steerer tube? It'd take ya ten minutes.

The steerer tube is a test piece for the frame. I want to find something that is gentle on the paint and decals but will remove rust (on the internal and external sides of the tube) whilst being as safe an acid as I can find to work with. The idea is to find the weakest solution that will work, even if that take some time. I will keep going up in strength until I am happy with the result and test a fresh test piece with that mix strength.

The idea of the “cup” measurement is that anyone who wants to replicate the bath strength can do so with a store bought measurement.

I must admit I just want to pour some in a bath and dump the frame in but I want to be able to do some more with the least messing around in the future! I will see what it will do to aluminium at a later date as well.

Quick check before work. Rust on steerer tube was just sitting on surface. A VERY light brush with a small wire brush lifted the rust off. Not sure if the paint around the crown race is lifting, will take out later and dry to see if any of the paint has been affected.

The next step is to put one more cup so it equals 1 cup per 5litres of water and drop something rusty in and see if that would work quicker without paint coming off, maybe turn the fork around?



Before light brush

After light brush.

2 days in 2 cup/15lt plus 1 day 3 cup/15lt results. It has taken the rust off nicely. You can see a little chrome lift where I expect rust had sat underneath. Where the chrome is still there it has made it very shiny. So I expect tarnished chrome would come out well, the chrome on this stem was long gone but it has cleaned up.










I have left the fork in because I want to see when it starts attacking the blue paintwork. It is lifting near the crown race but is that because rust was sitting underneath? The rattle-can black is very fragile so I expect that to come off, but the factory blue, how long can I leave the frame in the solution without fear of stripping the paintwork is what I am trying to find out.


Now what will it do to aluminium? Just gone in, so will pull out tomorrow, 24hrs in a soak. What will happen? Dissolves? Lol.

Now this is interesting. The black rattle-can paint is starting to come off with ease. I just rubbed with a scratch free scotch pad. You will see the fork decal has remained intact. The factory blue, is as of yet, untouched. This would be a great help if you find a frame that has been er, “custom painted” over the decals, to remove poorly prepared paint over factory paint. The parts that have lifted on the stem would have had rust underneath I think.

The aluminium hub is cleaning up. The metal grease seal on the ends has brightened considerably. I put it back to see what happens if you leave it longer than required to clean it.

I have noticed some of the blue paint lifting but around areas of damage, i.e. the brake bolt hole. The aluminium hub had black streaks, perhaps the anodising coming off? The black streaks mostly rubbed off. Lets see what a couple of days does! Everything has been popped back to see the reaction.

The fork has been in a solution for 6 days. Maybe tomorrow (7days) I will take the fork out, bi-carb, dry and see if the paint peels any more.

However I do feel confident of putting the frame into a tank and knowing what it leaves is the best I can expect. Any rust underneath paint means the paint will be lifted. I can live with that. The decals look like they may survive which is a bonus. I could also leave a frame for the weekend in the solution of 3 cup/5lt and be pretty sure I dont come back to any damage but rust free.

If the frame is not being painted or top coated, what to apply for protection?I have used this wax before in woodwork and small metal parts so will give this a go at protecting the frame.

Next time I build some wheels I will coat the rims first to see how it lasts. Maybe on my go to bike one rim only so we can see the effects over time?

https://www.axminstertools.com/axmin...ax-400g-105816

https://en.wikipedia.org/wiki/Microcrystalline_wax

https://en.wikipedia.org/wiki/Renaissance_Wax

Took the parts out today. 7 days for the fork is enough. Noticed the last threads have some metal “eaten”. Now I am trying to look at my photos to see if this was rust damage or the acid has done this. The threads at the top are ok, so do think it would have “eaten” them all the same rate.

Whatever, I now know you don’t need to leave a frame for 7 days, 12 hours would probably be enough at the 1cup per 5lt strength.

The aluminium hub does not seem any different. It did have the black smut over it which wiped off while still wet.




​​​​​​​

Took the parts out today. 7 days for the fork is enough. Noticed the last threads have some metal “eaten”. Now I am trying to look at my photos to see if this was rust damage or the acid has done this. The threads at the top are ok, so do think it would have “eaten” them all the same rate.

Whatever, I now know you don’t need to leave a frame for 7 days, 12 hours would probably be enough at the 1cup per 5lt strength.

The aluminium hub does not seem any different. It did have the black smut over it which wiped off while still wet.

Well, I split the top box (old one that was cracked on the bottom someone had thrown out, easier than building a frame, and double bunded lol!) and will use the bottom as a cover to keep the dogs out, but it holds a lot of water, about 75lt to cover the frame, much too diluted for an economical acid mix. I will find some plastic sheet and fill the voids with blocks to reduce the volume.

Any progress to report on this cool project?

Hi Velosophy. Well as you know life gets in the way of living. Work is demanding and energy has been in short supply! LOL.

I have given it a great deal of thought in how to restore. Full repaint and re-chrome or oily rag wipe-over? I am going for a mix of the two. I intend to take the rust away from the frame and clear coat what is left whilst polishing what should be polished and chroming what should be chrome. So in effect make everything except the frame look as good as it can. The frame has been the difficult decision.

I have been experimenting with rust removal mixtures. Evaporust is good but so expensive to do a frame. Sulfamic acid (which I tried earlier) is very good but I wanted something a bit gentler. I have found the best to be a mixture from Beyond Ballistics. Link below. Really, try it.

Title: The ultimate HOMEMADE Rust Remover (Better than EvapoRust)
The weather is against me now and the bike is stripped down waiting for its bath which can wait until the beginning of the new year when it warms up a bit. To be honest I have been distracted with gathering the parts for two Raleigh Clubmans and some Sturmey-Archer hub rebuilds.

I will document each stage but realistically it will take momentum early next year.

Sounds good. I have the same problem with project momentum with work and family.
Yes please document your process successes and failures we all benefit. I like the refinish ideas. Good luck with the projects