DIY Respray

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MikeF
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Re: DIY Respray

Postby MikeF » 14 May 2018, 2:32pm

Thanks for the reply. That link seems to used to dealing with bikes. I was surprised to find how many fairly local firms there are doing this work, and also that blasting can be done with different materials. http://foremostcoatings.com/blast-cleaning/3549128.
I'm not looking for any parts to be done at the moment, but I'm just trying to find out more for future reference.
"It takes a genius to spot the obvious" - my old physics master

PH
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Re: DIY Respray

Postby PH » 14 May 2018, 2:42pm

For the ease and cost I'd take something I needed doing to a local powder coater, who has some experience with bikes.
If I did want a go at DIY, I'd have a look at this stuff
https://spray.bike/

Vorpal
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Re: DIY Respray

Postby Vorpal » 14 May 2018, 2:54pm

We've had a couple of previous threads on painting...
viewtopic.php?f=5&t=99891
viewtopic.php?f=1&t=96246&p=891492
This one is about brush painting, but also has some good information
viewtopic.php?f=5&t=109989&p=1062671
“In some ways, it is easier to be a dissident, for then one is without responsibility.”
― Nelson Mandela, Long Walk to Freedom

mig
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Re: DIY Respray

Postby mig » 14 May 2018, 2:58pm

Si wrote:Ive rattle canned one (completely removing old paint with nitromoose, etch priming, spraying and laquering), and hammerited another. The initial finish was ok but it just d0esnt last like a proper job. Indeed, when you take into account the expense of the materials, the faff, and how you'll have to redo it sooner you are probably better off going to your local powder coater.


nitromoose is quite deer though.

cotswolds
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Re: DIY Respray

Postby cotswolds » 14 May 2018, 3:18pm

The rack on my tourer is still structurally sound but has a lot of surface rust. I feel that ought to be a suitable target for a DIY paint job, but my previous attempt was unsuccesful. Now I know why.

MikeF
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Re: DIY Respray

Postby MikeF » 14 May 2018, 9:27pm

mig wrote:
Si wrote:Ive rattle canned one (completely removing old paint with nitromoose, etch priming, spraying and laquering), and hammerited another. The initial finish was ok but it just d0esnt last like a proper job. Indeed, when you take into account the expense of the materials, the faff, and how you'll have to redo it sooner you are probably better off going to your local powder coater.


nitromoose is quite deer though.
:)
"It takes a genius to spot the obvious" - my old physics master

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willcee
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Re: DIY Respray

Postby willcee » 14 May 2018, 11:50pm

The nitromors thats on sale these days is totally emasculated and won't shift paint ime... the product name escapes me , there is something that bodyshops use but only available in specialist paint supplies motor factors for removal of cellulose[sp] and 2k paint.. and will need gloves and eye protection as did the old nitro.. will

David9694
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Joined: 10 Feb 2018, 8:42am

Re: DIY Respray

Postby David9694 » 15 May 2018, 7:16am

If you’ve got one bike to do then consider getting it done professionally. I’m an idiot with a rattle can. I did two frames with Bike.spray powder coat as my first efforts - results ok from a distance or in a photograph. I’ve now started using car paints.

Best painting conditions are best riding conditions. I pay about £100 a time for a 531 frame from Ebay. I spring the rear by trapping it in a workshop draw and bearing down on the frame - measure - go some more, flip it over, etc. I found I needed a thinner headset drift for 1” cups.

I rub down existing paint (I don’t take on complete rust bucket or damaged frames) with alu oxide paper to get it smooth all over and clear any rust spots (doesn’t require a warm day!) and clean up with white spirit. I’m sloppy about masking my threads, but so are some pros - I’m happy to tap/clean anything that needs it.

On goes two coats of primer. A gentle rub down with finishing paper or wet & dry and more white spirit.

I’ve challenged myself with various paint effects, so Holts enamel red, with silverhook white box lining done with 1mm pinstriping tape for example. I like doing a white contrast head panel, but haven’t found an easy way to mask all those round edges.

Monster pearl paint went on superbly and seems tough; a two-part white pearl from another company was almost a bridge too far for me, but maybe I need to pay more attention to the temperature - I don’t have the ability to spray indoors.

A broom handle clamped in a work stand makes a reasonable way to hold the frame.

A silverhook metallic red frame doesn’t seem all that robust, as has been said - a lot of touching up needed. I did a pearl white seat tube on that one which looks great - if you don’t look too hard. Another slightly more successful and resilient go was with sliver and a red translucent overspray paint from Germany, but it wasn’t quite the flamboyant I’d hoped for.

What I really crave is to replicate that flamboyant finish and that project is ongoing now. So far, we’re on a silver midcoat, with another to go on - needs to be a more grainy, sparkly silver - the Holts first silver mid coat is too smooth, I think. Then I’ve got some Canbrush red “candy” paint lined up. I know it’s a nice effect coz I got ahead of myself on the forks one day when the silver hadn’t fully gone off and part of it dissolved.

Some of the lugs have got cutouts in this frame, which I’ve filled with Humbrol Maskol over a white base so I’m hoping to be able to pick that out - should be very pleasing if it works.

Lug lining with a gold or silver Sharpie - the cheat’s way!

A Harry Hall frame has the name stamped at the top of the stays and on the fork shoulders and I’m attempting the same thing there - flow the maskol into (and around) the lettering, then wipe it off the main surface with a finger before it knows what’s happened.

I get decals from Stickers Planet- a good choice of fonts, colours, orientation and importantly, sizes. I name my restored bikes after a village near me and I’ve created a simple head badge design with help from an artist, based on a local landmark, which Stickers Planet printed for me. All take rattle can lacquer fine. I’ve also had a couple of pairs of handlebar ends made using the design, but this is getting a bit on the dear side now and I should probably stop.

Zanda
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Re: DIY Respray

Postby Zanda » 15 May 2018, 10:50am

I've done half a dozen steel frames and have found the most cost effective results come from:

rubbing down rust spots, then
using primer coat all over, then
brush coating the tubes, then
spraying the joints, drop outs, bosses and BB (i.e. the fiddly areas!) then
spray coating the tubes to unify the finish

Rust is generally worst at downtube, BB and around any cable housing lugs on the top tube and needs to be removed. It spreads in quite predictable ways from a rust spot, so you can find the edges of a rust patch. It's rarely necessary to remove all of the factory paint from a frame, as long as the metal is rust-free and any factory paintwork is sanded to give a key for the next coat.

I'd suggest choosing a similar colour to the factory paint. That way any chips show up less. In addition to this, I've found that dark colours require fewer coats than light ones.

The advantage of brush painting the tubes is less waste, since as MickF says upthread, a frame tube is a small target for a spraycan, and more paints misses than hits. The advantage of spraying the joints and the fiddly areas is the time savings. Choose brush paints and spray paints that are compatible, i.e. paints that don't react with each other. Test for compatibility before starting.

With almost all paints, the longer you leave it between coats, the tougher the paint. This however means you need a spare bike to ride while you're working on a frame. At each stage, the most recent coat needs to cure hard before the next one is applied.

I've found it convenient to hang the frame from a washing line for the painting, with somewhere else to store it while the individual coats are curing.

Meticulous cleanliness helps to avoid the paint flaking or peeling off. This means avoiding touching a paintable surface with fingers and/or cleaning and dusting the surface with a dry paint brush before laying down a coat.

As mentioned, retouching will need to be done sooner than with a factory paint job, though this was needed only on the top tube on my latest frame (where I used the method outlined above).

I've kept notes, mostly for myself as a record of what has worked. They can be read here.
Last edited by Zanda on 16 May 2018, 10:42pm, edited 2 times in total.

hamster
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Joined: 2 Feb 2007, 12:42pm

Re: DIY Respray

Postby hamster » 15 May 2018, 2:28pm

My experience is that rattle can paint chips so easily that it looks awful again in no time. If you don't like powdercoat (and I wouldn't have it on any frame with nice lugs) then a stove enamel is a good alternative...which means a bike refinisher.

I know that Baz down the pub who is a car sprayer can do it for £25. :wink: Baz usually discovers the hard way its different spraying bike tubes and that the auto spraygun is too big to get into all the crevices.

Greystoke
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Location: Lincolnshire

Re: DIY Respray

Postby Greystoke » 19 May 2018, 6:44pm

I stripped an early 90's mountain bike and re-sprayed it with tractor paint with a spray gun. The biggest issue is the paint reacting with any trace of the old paint.
Tractor paint is really hard wearing. We use it on our rally cars.

crazydave789
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Re: DIY Respray

Postby crazydave789 » 19 May 2018, 11:21pm

I repainted a second hand alloy frame last year when mine cracked on the head tube.

a quick run down to key the paint after I cleaned and de stickered it then some primer and then I used textured black bumper paint - basically spray on plastic which looks like old skool marin paint when they went through the grey teflon coating thing.

cheap and cheerful, easy to touch up and you don't have to be a great sprayer.