lacro

I am currently rebuilding a 1973 Raleigh SC. Build thread here. The frame needed some re-brazing so the paint was destroyed. I am seeking advise for doing the repaint.

I got most of the paint off the frame with paint stripper. It still needs more work on the lugs, and a few areas that still have some paint. I was able to find Garnet blast media that is much less aggressive than typical media used for industrial sand blasting. However, the weather is not cooperating. I woke up to it snowing yesterday

When (if) it ever gets warm enough to finish cleaning the frame, and prep for paint, I will need to decide which way to go with painting. With the partial chrome stays, and fork, there isn't a whole lot of frame to paint. For those that have done their own frame painting, I seek your input.
Here's some of my possible paths:

1. Etching primer, single stage lacquer rattle can
2. Etching primer, two stage (base/clear) lacquer rattle can
3. Etching primer, single stage enamel rattle can
4. Etching primer, two stage (base/clear) enamel rattle can
5. Any of the above four choices, but decant the rattle can, and use my touch-up gun, and compressor to spray
6. Automotive single stage paint system, primer/color, and use my touch-up gun, and compressor to spray
7. Automotive two stage paint system, primer/base/clear, and use my touch-up gun, and compressor to spray

The Automotive paint route has many choices of paint types, but it is expensive, and I may have to buy more than I need for the job. I know it's a lot better than rattle can paint, but I am leaning toward the rattle can, either direct from can or decant/spray gun method. Lacquer is much easier to spray from rattle cans than enamel, but probably lacks the durability? Any and all suggestions welcome....

DIMcyclist

I'd say route 4. Admittedly, I'm biased, since that's the way I usually do things.

You seem to be (very) familiar with the process, so the only suggestion I'd make would be to see (assuming you have your paint mixed at an auto paint shop) if they can prepare it ready-made for a gun system. Since you already have one, I'm sure you're fully aware of its superiority to rattle cans, both for general control & elimination of overspray. Aside from being a little more economical in terms of usage/ coverage, there might be a price break if they don't have to sell it in an aerosol can.

Edit: just checked out your build thread; that's a really beautiful frame; looks like it's be worth the effort.

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squirtdad

you might want to add sandable primer after the etching primer.

I have used both rattle can and automotive. The rattle can is hugely less durable, so you need to decide if the cost is worth the durability......especially as the amount of work that goes into it is huge

pics when it it done please

DIMcyclist

Sandable primer is usually never a bad thing but speaking from personal experience, if you have lot of scrollwork in the lugs it can get tedious.

However, with regard to rattle-can being generally less durable, I think you're mistaken because it all comes down to the paint. I agree that the stuff you get off the shelf at Fred Meyer & AutoZone is inferior product, but that's because of the paint itself, not the delivery system. The paint doesn't care if it's sprayed through a gun or a can; what matters is what it's made of-- whether it's a true, solvent-based enamel, an 'acrylic enamel' (aka: 'alkyd'), or a lacquer; each of these are different formulas, and all of them are available in rattle-can form.

While I generally use an airbrush for a job like this (you can't beat the control you get with an airbrush), I have used rattle-cans to good effect; however, in both cases I've used real enamels, and had them made at a custom shop; in the case of the rattle-can paint, using the Omni-Fill system.

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Kilroy1988 

While we're at it, I'd love to know what kind of rattle can spray paint doesn't scuff easily. I used a basic Rustoleum primer and enamel combo on my last build and am extremely disappointed with the quality of the paint... I have access to an automotive paint shop but do not really want to bother my uncle about using his facilities for a couple of budget builds I'm currently working on.

Salamandrine 

Yeah +1000. It is not the delivery system that matters, it's the material inside. It's kind of like beer. Canned beer is cheap beer, right? Well, not always. Paint is the same. Some paint shops will fill cans for you with good stuff.

Spray cans a perfectly acceptable size for a bicycle. Realistically, the overspray is going to require some hand wet sanding regardless to get a professional looking finish.

For a cheap enamel, the Rustoleum Professional is pretty decent. Takes a couple months to fully harden. It might respond to baking, I didn't try it. FWIW I do not like the 'professional' clear at all. It reacts badly to sunscreen and turns to gum. The standard Rustoleum is better. I'd assume that it's alkyd based.

The Brits still use stoved enamels. It's a proven tech, and very durable. I have stoved Sherwin Williams industrial enamel onto metal furniture, and go it to dry very hard in a few hours. The 'stove' was a couple homemade heat lamps. Problem is it's not easy to find quality stoveable enamels in the US.

So for a very high quality finish, 2 part auto paint is probably the best choice. HOK or whatever. Just be sure to wear a respirator. The stuff is poisonous.

crank_addict

Paint can be fun or a nightmare. Also a large and technical topic.

Being super abbreviated-

Immaculate prep

Immaculate handling of the frame during process

The environment (clean, low low humidity, reasonable room temp)

Use only proven product(s). This is not the time for experimenting. If going automotive grade, definitely follow the maker's specs -stay with one label if possible or what the supplier alternates have approved, drier additive, hardener etc..

Practice painting other tubes prior to your project. The compound angles, tubing is much different than flat or large surfaces. Consider the atomization and flash. Think ahead, strategize what works for best for you in handling spraying apparatus (regardless of rattle can to spray gun).

Light multiple coats, proper set between coats is always best.

There's been great improvements in off the shelf spray cans, and chemistry. Differ on those who still believe there's no longevity or durability. Rustoleum 2X in some pigments is pretty good and very affordable. For better control, highly recommend using a handle adapter.

Getting into the subject of using HVLP sprayer, including 2 part urethane top coating, etc. is lengthy but go for it if you have the means or access. This includes having a proper 'high air volume' source... not talking 'pressure'.

Will add, poorly sprayed main coats -be it rattle can or sprayer can sometimes be saved... depending on the formula, by getting one to spray a quality (well atomized using HVLP) urethane clear topcoat.

Allow sufficient curing time before assembly

Good luck!

squirtdad

Agree there is a wide variance in what is available in a can.....and living in California there are a lot of restrictions as to what can be sold.in spray cans

When I painted with auto paint (2 part cataylzed clear) I used the Pre-Val sprayers....pour the paint in the little glass jar and do it your self rattle can. worked pretty well

Basically I have come to the conclusion that unless it is a really nice frame you are better off just getting it powder coated. My first paint job (rattle can) is so goofed up now, I am very close to stripping the bike and sending it off for powder.....

it is all good learning

and don't forget a good respirator/mask that should be the first purchase

DIMcyclist

You can still get them in Japan as well.

For hand wet-sanding & respirators; tried & true.

Solvent-based polyurethane enamel is usually the best way to go. It dries with the hardest finish & has the fewest complications.

Lacquers give a hard, truly beautiful finish, but take a lot of patience: while the paint might dry to the touch in just a few hours, it can take weeks for it to fully cure (some take up to a month). One of its advantages however, is that it as it cures, it naturally hardens. I should point out that lacquers are also highly volatile; very flammable (DON'T light a match near it; don't inhale it). Best only applied through a high-volume/ low-pressure (HVLP) gun system, either by a pro or someone with a lot of pro experience.

While most of the rattle-can paint you find in stores is acrylic (which will not bond properly to solvent-based paints or primers), alkyds (latex-based polyurethane) are a slightly different animal. Alkyds (2 & 3 part car paints) are quite good and are usually custom paint, but- like lacquer- they're tricky to use, albeit for entirely different reasons. In the case of alkyd paint, the difficulty comes from the fact that the reducer is also highly volatile (it's similar to acetone in that regard), which means that it's flammable, evaporates very quickly, and clean-up MUST be immediate because the hardener will set in the little ducts of your gun system & be a complete B1#@% to remove afterwards. (Edit: yes; unfortunately speaking from personal experience. ) When you use the right amounts of reducer & hardener, the paint will set up quickly, which leaves you very little time for clean up.

It takes about 3 or 4 days for a 3-part alkyd to properly cure (off-gas), and to get a nice depth of color takes about three coats (so, 9 days), but once done, you'll have a sandable, polishable surface that will be fairly durable- if you mixed your paint correctly. If you didn't use enough hardener, it will peel off in no time. Alkyds are also tricky because you really have to pay attention to compatibility with your primers. If you didn't, it'll also peel right off; it's a known issue with bikes painted at the factory with Imron.

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Kilroy1988 

I see some rattle can lacquers on the market... Valspar, Rustoleum... I'm a patient guy, and know my prep work is usually pretty spot on, but I keep chancing cheap stuff and am not satisfied. Mostly the rustoleum acrylics. If a rattle can lacquer will do much better than that, I'm willing to let it sit between coats and all that. If it may still be risky, I'd have to pay more than I want.

RobotGuy

DIMcyclist

Never skimp on your materials; in the end, it's always a bad idea. You don't want to waste time & effort over cheap paint.

Epoxy-based enamels are easily the most durable; it's basically marine-grade, but you don't usually don't have as many color options as you do with either type of polyurethane.

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andr0id

Well, that solves the big problem with rattle cans in that a durable paint needs an activator, but you have to add it right before you use it.
Activators make you paint cure *hard* regardless of temp and humidity. (heat will speed up the process though)

RobotGuy

DIMcyclist

Sure enough... With epoxy-based enamels you have to get it right the first time, you don't really get a second chance.

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Wulf

I went to the auto paint store and got everything I needed. Etching primer. Automotive enamel they put into a rattle-can. 2-part clear coat. This last thing comes in a special rattle can with a plunger that causes the paint and catalyst to mix. It can only be used for about 18 hours once mixed.

Kilroy1988 

I'm sold on the 2k aerosol products for my next project, just because it's black. After I get another frame done then I'll move on to having some stuff mixed up for me at a local shop.

Really glad I jumped in to ask and learn! Thanks for the thread and all of the replies. Good luck on your Super Course, lacro!

-Gregory

lacro

How much did you spend for all that including reducer?

lacro

I know the automotive paint systems are the best, but by the time I add up all that's needed - reducer, base, clear, hardener it's probably north of $100. then add new Raleigh decals for another $40-50. For a bike in excellent condition is only worth a couple hundred dollars at most. The 2k aerosols is worth a look, but they are expensive too. I am not trying to cheap out, I just have a hard time putting more money into paint or powder coat than the whole bike is worth. How about implement enamel, anybody ever tried that?

Wileyone 

I think next to the prep work the clear coat is the key. The 2k stuff is nice. But if you know a good body shop see if they might shoot some clear for you.

sloar 

I've painted around 20 frames, so I can tell you how I've done it. Frame media blasted, then I sand down the frame with fine grit paper. Sanding smooths down the metal but also reveals and imperfection like tiny dings. I use Dupli-Color ready to spray Lacquer paint system. Quart of primer, color and clear totals $70 plus you will need acetone to thin the paint down a bit. Very easy to work with and a very fast set up time. I use a detail paint gun from Harbor Freight that runs $14. Great results and its pretty durable. I had one that didn't turn out so great but that was my error from spraying to thick and not enough time inbetween coats.

Kilroy1988 

After I repaint the two Super Courses that I currently have waiting for restoration, I will never buy a common or cheap frame to restore again - for precisely that reason.

Fidbloke

I noticed that a lot of people on this thread are using the term 'enamel' for a lot of different paint types - even 2-pack types.
To me in Britain, 'enamels' are either stove enamel, which is a bit specialist but still available here, or the synthetic enamels (which I think are usually alkyd based).
We also have the choice of Cellulose Lacquer, Acrylic Lacquer (the most common one in the aerosols in most motor factor places now), alkyd enamel and 2-pack.
Our 2-pack is either the old iso-cyanate stuff or the newer water-based stuff which you can use with ordinary paint masks. Generally, the water-based stuff is used in a base/lacquer system with a harder 2-pack lacquer on top.

I was wondering if 'enamel' was a general catch-all US English term for a whole lot of different paint types?

Kilroy1988 

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

There are in fact a lot of different paints marketed as enamels, few of which are coherently related to traditional enamels.

noglider 

I spent only about $20 on paint for my Raleigh. I don't think you need to spend $100 on materials.