Brompton 'Lacquer' Finishes

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LiveFree
Posts: 65
Joined: 25 Mar 2019, 3:57pm

Brompton 'Lacquer' Finishes

Post by LiveFree »

Hello all-

I am hoping that you might be able to advise about something- I know that there have been a fair few stories of the raw lacquer (clear powdercoat) finished Bromptons having problems with surface rust/other blemishes appearing- even on bikes that are not so old; but I am wondering about the new 'flame lacquer finishes'- would these also run a similar risk of rust/blemishes appearing/showing?

And equally, are these fancy 'lacquer' finishes more difficult to deal with in terms of touching up chips/scratches etc than something like the standard black Brompton? I can see that with the matt black finish (although not as useful at hiding blemishes as gloss finishes) if any touch up work needs to be done (and by the virtue of it being a folding bike, I think the chance of that is quite high!) it shouldn't show too much; whereas with the flame lacquer I can imagine it would really stand out. I would be interested to hear other people's experiences/opinions- I think that the black Brompton, whilst not as aesthetically pleasing to me as the flame/raw lacquer, for a folding bike being kept in the long term might be a better bet than the fancy finishes.

Any input from others would be gratefully received :D
AndyA
Posts: 526
Joined: 21 Mar 2009, 9:16pm
Location: Edinburgh

Re: Brompton 'Lacquer' Finishes

Post by AndyA »

I think this sort of corrosion/blemishing happens under all kinds of powdercoat and it's only visible on the clear powdercoat frames. I don't think it will be as visible under the flame lacquer as the clear, the flame lacquer is close to rust in colour! I'm certain it would be a pain to touch up. That said, it would be the colour I'd choose. Or maybe purple
alexnharvey
Posts: 1923
Joined: 10 Jan 2014, 8:39am

Re: Brompton 'Lacquer' Finishes

Post by alexnharvey »

Rust spiders are a feature now, rather than a bug.
LiveFree
Posts: 65
Joined: 25 Mar 2019, 3:57pm

Re: Brompton 'Lacquer' Finishes

Post by LiveFree »

Many thanks Andy- what you said makes total sense. Alexnharvey- I'm afraid I didn't quite understand your response: could you please explain it? Thank you :D
alexnharvey
Posts: 1923
Joined: 10 Jan 2014, 8:39am

Re: Brompton 'Lacquer' Finishes

Post by alexnharvey »

LiveFree wrote:Many thanks Andy- what you said makes total sense. Alexnharvey- I'm afraid I didn't quite understand your response: could you please explain it? Thank you :D


Rust spiders is a term for the filigree rust patterns that develop under the lacquer. I think they're inevitable with these finishes, so if you want that look you accept them.

http://groovycycleworks.blogspot.com/20 ... f.html?m=1
LiveFree
Posts: 65
Joined: 25 Mar 2019, 3:57pm

Re: Brompton 'Lacquer' Finishes

Post by LiveFree »

Aha, many thanks Alexnharvey- now I get you. Cheers for that- again, good information to have :D
Brucey
Posts: 44529
Joined: 4 Jan 2012, 6:25pm

Re: Brompton 'Lacquer' Finishes

Post by Brucey »

its more usually known as 'filiform' corrosion I think.

Its worth comparing the performance of clear coating in other applications, e.g.

1) on top of other paint finishes. They have got this sorted out now, but a few years ago every change in paint chemistry made for a new, improved risk that the clear coat would just fall off the underlying paint. Very nasty.

2) On alloy car wheels, eg on top of turned aluminium finishes . Doesn't last that long; a couple of UK winters is often enough to cause the finish to go white and crusty under the edges of the clear coat. A whole industry exists for refinishing alloy wheels and this is a good part of the reason why.

3) over bare steel. At best it works about as well as any other coating that isn't properly chemically bonded to the metal surface, and hasn't got anything in it to retard the corrosion process. i.e. not very well.

Crummy paint finishes may well have filiform corrosion beneath them (often you can see this raised 'veins' in the paint surface), but most good paint finishes don't. A good wet paint system ought to comprise a passivation treatment, an etch primer, an undercoat that resists corrosion (e.g on steel containing zinc) and then further colour coats before the clear coat. The multiple coats give the paint finish the overall combination of properties that is desired.

You can do a pretty good job with a two-coat powder coat too but the overall finish is thicker and less smooth overall, so isn't the best way with steel frames which have delicately filed lugs; the definintion is lost, and the hours of work by the framebuilder is wasted.

Overall verdict; clear coat direct on steel is a load of nonsense, for looks over anything else. It is only going to last if you ride/store your bike in bone-dry conditions.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
LiveFree
Posts: 65
Joined: 25 Mar 2019, 3:57pm

Re: Brompton 'Lacquer' Finishes

Post by LiveFree »

Great information- thanks Brucey :D I'm not sure if Brompton's clear powdercoats count as being painted directly on bare metal exactly- their solution to this seems to be to pre-treat the frame with an iron phosphate coating, to prevent any corrosion occurring under the clear coat. In practice though, from what I've seen- this doesn't seem to be a sufficient solution, as there seem to be more than a few of the 'raw lacquer' Brommies about with filigree rust showing.
It does indeed seem that the clear powder-coated Bromptons are a case of form over function! Good for anyone thinking of buying one to know :o
CathM
Posts: 77
Joined: 1 Nov 2019, 5:20pm
Location: Cumbria

Re: Brompton 'Lacquer' Finishes

Post by CathM »

Hi everyone -

I’m posting on an old thread because I have a Brompton with a raw lacquer finish which has developed corrosion around the rear dropouts and small areas of filiform corrosion on the chain- and seatstays. Our garage, while not bone-dry, has not caused our bikes to rust significantly until last winter when it was particularly damp, and the Brompton, being so close to the ground, was the only one that suffered. I don’t use the bike if the roads have been gritted.

I bought the bike second-hand in 2019; it was the model I wanted, in “as-new” condition, at a good price and the seller lived not far away, which is a big plus as I don’t live near a city, where most Bromptons live. So while the raw lacquer isn’t what I’d have chosen I wasn’t going to quibble about the colour! I’d have chosen something less eye-catching, but I thought that if it did rust at least I’d be able to see it and I wouldn’t have to worry about colour-matching paint. Of course, now I see the problem; I can’t use a primer and the bare metal I’ve uncovered is going to show up when I retouch it.

Does anyone have any advice of how to deal with this? There is a Brompton touch-up lacquer available but is there any way of applying a corrosion inhibitor underneath that won’t be glaringly obvious? I’m tempted to prime and paint the drop-out black, which wouldn’t be too conspicuous, but the stays are a different matter. I’ve found Jenolite “Rust Shield” on the web; is this a suitable coating for the job?

One thing’s for sure: “Bronwen” will be spending next winter indoors.

Any suggestions would be much appreciated.

Catherine.
alexnharvey
Posts: 1923
Joined: 10 Jan 2014, 8:39am

Re: Brompton 'Lacquer' Finishes

Post by alexnharvey »

You either (A) have the existing coating removed and have a better job done or (B) do your best to keep it going with small touch-ups until A becomes unavoidable.

One advantage of the brompton is that you could have rear triangle recoated in a different colour and eke a few years out of the main frame?

Brucey recommended a product called owatrol for touch-ups. It is mentioned in a recent thread on paint respraying viewtopic.php?f=1&t=143737&hilit=owatrol
CathM
Posts: 77
Joined: 1 Nov 2019, 5:20pm
Location: Cumbria

Re: Brompton 'Lacquer' Finishes

Post by CathM »

Thank you, Alex. I was afraid a (partial) respray might be the answer. It grieves me that my “new” bike, which was pristine a few months ago, now has all these blemishes, and I’d like to put off the evil day when it needs re-coating as long as possible. I’ve just read the article you provided a link to in August 2019 and it doesn’t make me any happier!

I’ve looked up Owatrol and it looks promising, at least to stop the problem getting any worse. The manufacturer’s blurb states that it can be used as a base under a top coat, so I’ll try that with clear lacquer on top. I’d be interested to know how others have solved the raw-lacquer retouching problem in practice.

Cath.
rogerzilla
Posts: 2887
Joined: 9 Jun 2008, 8:06pm

Re: Brompton 'Lacquer' Finishes

Post by rogerzilla »

Argos repainted mine when it was less than a year old. The original (ivory) powdercoat just flaked off. The flam red that Argos sprayed on is still pristine 11 years later.
grufty
Posts: 135
Joined: 26 Sep 2017, 2:24pm

Re: Brompton 'Lacquer' Finishes

Post by grufty »

I've noticed rust on the rear triangle of our bikes, more so on a newer than older model. This area of the bike does get a pasting from road crud, so I've come to the conclusion that perhaps the rear triangle should be considered as a consumable, especially as sooner or later the main hinge will need replacing.
CathM
Posts: 77
Joined: 1 Nov 2019, 5:20pm
Location: Cumbria

Re: Brompton 'Lacquer' Finishes

Post by CathM »

Thanks, Grufty and Rogerzilla - I'm shocked at your bike needing a respray after only a year, and while I appreciate that the back end of a Brompton may not last as long as the main frame, I'd been thinking in terms of decades, not years! However, the Owatrol's arrived and I hope I'll be able to reduce the problem. I see that Trevor Cox has been having similar (but worse) problems and have read that thread too.
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