Frame painting
 

I've just found an abandoned old bike. It's a Benotto, and I don't know anything else about it except that it's probably older than me (35 years).

I've not had time to inspect it carefully, but it seems to be in "decent" condition. It has mavic wheels that spin well and are true, a 6sp freehub, double chainrings on a Benotto branded crankset, downtube friction shifters, a Suntour RD and brakes that work with (relatively) new pads.

The chain and cassette are totally rusted, so they're a direct replacement. The frame seems to be structurally ok, but has a considerable amount of rust, specially on the left seatstay. I'd like to repaint it.

I've never painted a frame before. I'm going to attempt it with a spray can as I have no better means. I've seen that it's a good idea to remove the old paint before, but some people say to do it with sandpaper, others say it's better to use chemicals... what do you recommend?

I understand that when I have the frame sanded, I should use an anti-rust primer, then the paint, and then a clear coat. Correct?

When I paint it I would like to restore it to its original condition, so I intend to buy replacement stickers. Should I place them under or over the clear coat?

I've seen people that attempted this and had problems with the paint chipping. How do you avoid that?

Thanks!

Steel frame? Sandpaper will work, but it's a tedious job, and hard to reach tight spots. Chemicals are messy, toxic, and also tedious. Quicker to take the frame to someone who has a sandblaster and remove the paint that way. Once the paint is off, consider powder coat instead of paint. Lower environmental impact and more durable than paint. A clear coat over decals will help protect them from damage, but whether or not you can clear coat over decals depends on the decal. Check with the supplier.

My solitary attempt at repaint was in the '70s, somewhat satisfactory. I stripped the frame with chemicals. Ideally the frame
should be sand blasted with a mild media as the best approach to rust and paint removal. Frames, especially with lugs,
are very difficult to fully clean. The amount of work is considerably greater with sanding than chemical removal but both
are labor intensive. Residual rust patches should be passivated with a phosphate based prep, which are commonly
available.
I would closely examine the inside of that bike tubing that you can see with mirror/light for internal rust. Ideally the inside
of the frame would be passivated as well then, post paint, treated with such as Frame Saver.
It is impossible to prevent chipping, but most spray can paint will be thin layers even with multiple applications and
hence more easily scratched. Even powder coat, which is tough, can be scratched. There are paints which are
tougher but generally dangerous to use and expensive. Wrap is another possibility which is used on motorcycles and
cars but needs pro application. Google wrap versus painting for more info.
I would put stickers under clear coat.

I recently had a tandem powder coated, which included a transparent clear coat which would require decals/stickers
on top of clear coat. I did get a set of stickers from the maker but it turned out that applying them required more
experience than I had. The general idea was the decal was in a sandwich of protective clear plastic, and one side
of the decal was sort of sticky, the protective layer was pealed off and the decal placed and then the outer protective
film removed. In my case the decal repeatedly came off when I tried to remove the outer film. $50 down the drain.

I would go with rattle can epoxy primer and paints. They cost more than standard but certainly will be durable.

If you really want to do this nice I'd start with getting it bead blasted, call around to some painting places and you'll probably find somewhere that will blast it for a reasonable price. Sanding is the worst way to strip a frame unless you're only goal is to sand down small areas to create smooth transitions to the surrounding paint and get rid of old rust or corrosion. Chemical will work fine but expect messy and do it outside.
But the better your starting surface the better the results. Cans will not typically produce a quality result unless you're already skilled with using a spray can, runs and drips will abound. Spray primer isn't so bad, look up wet sanding, its what you should do for the primer. Also look up rolling on paint, there's a technique for rolling on enamel paint using a thinner to make really light coats that will dry reasonably quick and does lay down a nice smooth surface. I've actually seen really nice results on this. You will need to clear coat, enamel isn't that hard and the clear is stronger though final strength of the finish can take several weeks from what I understand if you aren't using chemical hardners to speed up the process. I also think clear looks better over the decals. GCN does a nice piece of the process of painting a new frame.
You may also find the place that does media blasting does powder coating and they may be able to come close to matching the color and it might be fairly affordable. I was charged 25.00 on an old frame since I was happy with the color they were using on a bulk batch of machined items. Typical I've heard are 75-150. You can clear coat over the top and best result will be primering and smoothing the frame first.

best bet is to find a local powder coater, who is experienced in bikes.....

best to remove all paint

rattle can will be not durable as compared to automotive paint but same amount of work

even rattle can will cost way more than you think


get a good mask 40 to 60 bucks right there

take all the parts off the frame

chemical strip the frame to bare metal

wipe frame down with paint prep, degreaser

handle only with gloved hands now

acid etch primer

sandable primer

light sand

Tack cloth wipe down

3 thin coats of color, watching recoat times

2-3 coats of clear watching recoat times

easy $80 to 100 in materials (if you don have a mask)

repeat powder coat is better option IMHO

I painted another frame just recently. I use aircraft stripper. It's a gel and I put it on with a paint brush. Waited ten minutes then used a pressure washer. 99 percent of the paint was off i repeated a few times in the hard to reach areas and used a dremel with a wire wheel. I used paint from spraybike.com there bike specific paints and are pretty good I used 2k clearcoat but spray bike also has clear coat and primers. This last frame was aluminum so I etched it and then primed. All said and done I probably had 7 or 8 hours into it. Also spent at least 70 dollars. If it's a project that you enjoy then do it yourself. It's not really that hard. In my area powder coating cost around $150 for a prepared bike frame. So if you figure in your time theres not much savings. Doing it yourself you get more color options. Any vehicle you see that you like the color google that make and model get the color code and then buy that particular paint online in a spray can. The automotive paint come in a kit primer pain and clear coat for $50 or $60. I have used them before too with good durable results. And when it comes to decals I put them on very last then use helicopter tape over them.

...the prep and rust removal are tedious to do by hand. The accepted professional way is to strip offf all the old paint, either mechanically or chemically.(You can buy paint stripperat HOme Depot that will take offf most of it, but doing it is a huge mess, and takes several hours.) Many people just bite the bullet on the cost and take it to someone who does blasting and has the equipment to do it. Prices for this are all over the map. There are also some places where they do refinishing of things that have chemical dip tanks.

If there's significant rust, sand it smooth in those spots, down to bare metal. Use a self etching automotive type primer.

The most durable clear coat by far is the Urethane 2 part stuff, which now comes in spray cans with an internal 2 part mixing process. It goes on last, over your color coats and the decals or stickers you put on over that. Wear a respirator when you paint, and do it outdoors if at all possible.

https://cimg8.ibsrv.net/gimg/bikefor...fe4b874092.jpg

Thanks everyone for the advice. I know it's easier to have a professional do it, but I prefer to do it myself and learn something new.

I also know it's probably not cost effective to repaint the frame. I don't really care. Repairing the whole bike won't be cost effective as I doubt I'll ride it regularly, anyway. I just want to restore it for fun.

I've just got home and had a closer look at the frame. It has a couple of spots that have lots of rust, but it seems structurally solid. I think I won't know if it's OK until I remove the rust and see whats underneath though. The rear wheel has lots of rust in the spokes too. Not sure if it's worth it to clean them or it's better to buy new ones. Fortunately it seems the RD and shifters are perfect. There's a bit of rust on the FD and brakes, but nothing difficult to remove.

Surprisingly, the bike has Look clipless pedals that are like new, and the chainrings also seem to have been recently replaced. Not bad for a free bike.

Here are a few pics of the bike and the more rusted parts:

https://cimg6.ibsrv.net/gimg/bikefor...1b8d578596.jpg
https://cimg9.ibsrv.net/gimg/bikefor...3ea53f5c0d.jpg
https://cimg0.ibsrv.net/gimg/bikefor...f1b0021865.jpg

Note to all: OP is in SPAIN, (Catalonia).


Nice looking bike, from a distance, I can see why you want to restore it. The amount of rust will
considerably increase the labor involved to get a good result single handedly. Once prepped
and passivated (but please look at the inside of tubes as possible as well) 3alarmers suggested
spray can epoxy is a reasonable choice IF you have an organic vapor respirator,
Looks one can would run €20-25.

Check out some of oldshovel’s videos on youtube. He does alot of repainting, and uses spray cans.

Thanks, I'll do that!

For now I discovered that I'm going to have a few issues. The seatpost is totally stuck. I somewhat expected it, but I've never dealt with a stuck seatpost, so that will be another first for me 😅

I've checked the rest of the bike and it doesn't seem that bad. I have to replace all 18 spokes of the DS on the rear due to rust. 1 spoke on the front wheel that's broken. The bottom bracket is toast. Inner and outer cables are corroded.

The rest of the components only need some light rust removal and maybe replacing some bolts which have corroded excessively. The hubs are also good enough and the cups and cones are miraculously free of pitting.

So in the end my biggest issues are going to be removing the seatpost and painting the frame 😂

Before you even start . . .

You must determine two things:

1. Is it a Made in Italy or Made in Mexico bike - OR - is it pre-1981 or post 1981.
2. What Modelo is it? 800? 850? 1000? 1500? 2000? 3000?

Because there are certain Benotto's that you DO NOT WANT TO RIDE. In other words, they become art or museum pieces for display only.

=8-|

Based on this page https://machiine.com/2015/benotto-classic/ i've narrowed it down to a 1984 Benotto 850, as it has Zeta tubing (according to a lightly damaged sticker on the frame) , Cherry brakes and Suntour VX derailleurs, which only coincide with that model. I think that the only things that are not original are the rims, probably the saddle (although it seems really old) and the headset, which has the year "2000" etched in it.

I'm out sure where it's made, but being in Europe I think it would be really strange if it was made in Mexico rather than Italy. I can't seem to find any serial number anywhere on it, although I'm not sure if the paint is original as the stickers are over the clear lacquer. Maybe it's hidden somewhere under the paint, I hope to find more clues when I disassemble everything.

Why are there some Benottos that can't be ridden? It's not like I'm going to ride it everyday. I just want it to work and be able to use it maybe once or twice a year for fun. After all, I have a modern, more comfortable bike for riding. Benotto's gearing will probably make the bike difficult to ride around here anyway. Climbs are way too steep to do them on a 42-26 unless you're The Incredible Hulk.

I'm a bit worried about the seatpost. Yesterday I was unable to move it even by a small amount. It's a really nice campagnolo seatpost, and would like to remove it without damaging it or the frame. It's made from aluminium, so I think galvanic corrosion has done it's job.

...in cases where you have already decided to repaint the frame, stuck seat post removal is usually pretty easy to accomplish. The reason for all the various recommended methods you see on the internet is that most people with this issue don't want to ruing the paint by heating. But you are going to take all the paint off anyway.

You need a small bottle of penetrating oil or ATF/acetone (mixed 50-50 and shaken). And you need a torch of some kind. I use mostly a simple MAPP gas torch, like plumbers use to sweat copper tubing joints. They are cheap and readily available here in the USA.

Heat and cool the post and the seat tube several times, applying the penetrant of your choice at the insertion of the post to seat tube, and from underneath, through the BB shell if you have it empty.

This will break the corrosive bond that has been formed and the post should come out pretty easily. Don't be afraid to use quite a bit of heat, because you don't care about the paint on there.

I've manually sanded the seatstay where there was the worst of the corrosion to see what was underneath. Good news: the frame is not structurally compromised.

However, it has slight pitting corrosion which I already removed but, thanks to the pits, the surface is not totally smooth. I assume I should smooth it out before painting.

What should I do? I smooth it with some type of epoxy? I just sand it until its smooth?

Here's a pic:


https://cimg4.ibsrv.net/gimg/bikefor...957743609e.jpg


Thanks!

Sanding primer from any store that sell automotive paint. Wet sand between coats. Sometimes they call it high-build primer.

Of course you need to consider what that is being top coated with. But if the top coat is particular about the stuff below it, then just use it's primer after the sanding primer.

This MAY be true and if the OP is lucky, it will come to pass.

But let me share this: a former friend who is now a professor of metallurgy had a seatpost get stuck in an Italian frame. He rode and raced that bike and obviously knew all about hydrostatic welding and corrosion on metals. But somehow he didn't keep up with greasing his seat tube. When his seat post got stuck, he worked at a national laboratory with all manner of machine shop, tools and chemicals at his disposal, in addition to other scientists and engineers on hand.

Well, let's just say they tried EVERYTHING on that frame to no avail. Despite using heat on the frame and liquid nitrogen on the seat post, it would NOT move! Into the dumpster it went. So be forewarned that this seat post may be irrevocably welded to that seat tube. Now the seat tube could be replaced by a frame builder, but the cost of said work would undoubtedly cost FAR more than the frame's value. That's your call.

So just know that it might come right out, or it may not. But you'll soon find out!

It will crack where the seattube meets the bottom bracket lug.

It's made in Mexico....the cracking issue at the BB applies to 850, 1000, 1500, 2000 and sadly, 3000 modelos after 1981.

While the 3500 was supposedly made in Italy, a few also were made in Mexico . . . cracking occurs in those where the downtube meets the headtube lug.

The diagnosis made by a frame builder here in the bay area was simply overheating during the brazing process.

The Benotto 5000 SL in Columbus MS / Gilco tubing was exclusively Italy - unaffected by this problem.

Basically, the only safe model was the Benotto 800 - made with plain Jane high tensile steel - which is much cheaper and heavier BUT a more heat-mistake tolerant material in mass production lines.

=8-|

If you love Benotto as I do, sand it, clean it, prime it, repaint it, clear coat it - and make it a nice showroom piece for your living room and shows....a conversation piece.

=8-)

Well, trying it is free. I'll report back with whatever happens.

It may be a while though. I don't have much time, so I'm going to be slow on this.

Well, as I said I doubt i'd ride it more than maybe once or twice a year on short rides for a bit of fun. The rest of the time I plan on hanging it on the wall at my future house , which is undergoing renovations now. To be honest, I see little reason to ride a bike like this regularly having a nice and modern road bike.

Do you really think it will break with such occasional usage? I understand it could break anytime, but the risk is way greater if you ride it daily which, definitely, I'm not going to do.

BTW, you seem to me like an expert on Benottos, so I have one more question: I've seen some have a heart shaped cut out on the BB. But mine doesn't. It has this cutout instead (sorry for the blurry pic). There's also a "53" stamped on the BB shell.

https://cimg4.ibsrv.net/gimg/bikefor...98a2ae6ef9.jpg
Does this mean anything?

...if I really loved a frame, and I couldn't get it to come out any other way, and I had access to a machine shop, I would remove the post destructively. Maybe that was too much trouble.

All the powder coaters in my area do their own stripping either by dip or blast, generally with fairly benign media. So
if you want a bike powder coated don't bother to try to strip it yourself. Powder coaters have access to an amazing
panel of colors with and without metal flaking. FWIW the urethane two part paint is only available in limited colors,
(rattle can variant) kinda like new cars these days.

Also if the seat tube breaks at the BB shell, at least that is not likely to be an instant crash, nowhere near stem or
bar failures where face plants are hard to avoid. Seat post break could probably be ridden home at a sedate
speed safely. Bike will feel weird but is ridable. Once I was ~10 mi from home when the down tube broke
in half at the downtube controls. Found a bit of electric cable and bound down tube to top tube and
cautiously rode home, had a lot of bounce.

If you find a painter or powdercoater who blasts off powdercoat, RUN AWAY! Old powerdercoat needs to be chemically stripped to remove it. It's too difficult to remove with blasting. And if someone DOES try to blast it off, they'll pick a grit WAY too coarse and eat into the steel (aluminum is WAY worse). After the powder is stripped, THEN the frame is bead blasted, a MUCH more forgiving media for your frame. So anyone blasting of powder on a bike frame doesn't know what they're doing.

Just an FYI.

A few years ago I found an old Benotto frame on the street that was a half finished project. The paint was mostly stripped and the derailleur hanger chopped off, probably to make it a fixed gear so I built it up as a single speed.
I removed the old paint with a wire brush in an electric drill, and painted with spray cans. Paint was from an auto-store (a GM color, I think) with SprayMax 2k clearcoat on top (2 cans). The new decals were under the clear cost as well.
No the lightest bike but the paint looked great - so great it got stolen a few weeks later.

https://cimg1.ibsrv.net/gimg/bikefor...f360599b72.jpg
https://cimg2.ibsrv.net/gimg/bikefor...d94e72ee99.jpg
https://cimg7.ibsrv.net/gimg/bikefor...c9f2db842d.jpg