Thinking of doing a custom paint job

[Dalton2250]

Hi guys,

I have a Focus Raven 2008 MTB, made in Germany & I'm thinking of re-doing the paint job, proper custom style.

Does anybody know what kind of metal/alloy the frame is likely to be made of? I understand this needs to be taken into consideration when doing a re-paint.

If not, how do I identify what metal type it is?

If it helps, it says 'German Lightweight Engineering' on the frame at the moment.

Also, in terms of removing the current paint, I've a friend who has a sandblaster to remove the old paint. Would this pose any risks/problems do you think? Is it better to do a hand-job (so to speak) and remove it with some kind of wire wool?

Thanks very much

Si

[JohnV]

Not sure about the 2008 model, but the 2011 Raven line has a carbon fiber frame and fork. I wouldn't go sandblasting carbon fiber. If you are going to repaint, I would suggest hand sanding or sanding with an orbital / vibrating sander. Orbital sanders don't tend to gouge or over sand the material like belt sanders do. They are also smaller and easier to handle and some (like the B&D Mouse) can get into some real tight spaces that belt sanders can't. However, hand sanding with a fine grit paper or emery cloth on carbon is the best.

If the 2008 model is aluminum, there are chemical solutions to remove the paint as well as light sandblasting. Just make sure that the chemical paint remover is safe to use on aluminum, as there are some that are not. A good way to tell if it is aluminum or carbon is to look at all the joints for welding marks. Some of the joints may look perfectly smooth, but if there is welding involved, there are at least one or two joints that will show up. A good place is to look at the area of the seat tube and seat stays where the joint is small and sanding the weld smooth is a bit more difficult to do.

[Dalton2250]

(06-01-2011, 07:49 AM)JohnV Wrote:  Not sure about the 2008 model, but the 2011 Raven line has a carbon fiber frame and fork. I wouldn't go sandblasting carbon fiber. If you are going to repaint, I would suggest hand sanding or sanding with an orbital / vibrating sander. Orbital sanders don't tend to gouge or over sand the material like belt sanders do. They are also smaller and easier to handle and some (like the B&D Mouse) can get into some real tight spaces that belt sanders can't. However, hand sanding with a fine grit paper or emory cloth on carbon is the best.

If the 2008 model is aluminum, there are chemical solutions to remove the paint as well as light sandblasting. Just make sure that the chemical paint remover is safe to use on aluminum, as there are some that are not. A good way to tell if it is aluminum or carbon is to look at all the joints for welding marks. Some of the joints may look perfectly smooth, but if there is welding involved, there are at least one or two joints that will show up. A good place is to look at the area of the seat tube and seat stays where the joint is small and sanding the weld smooth is a bit more difficult to do.

Thanks John, that's a brilliant reply!

You do like to spoil me with your wisdom don't you.

Ok, yeah, I've seen that there are some weldy kind of parts on my frame, does that mean it's alu or carbon? I'll more than likely do it by hand if it's carbon. Bit more pride with doing it that way eh!

Cheers fella

[JohnV]

If you have welds, it is most likely aluminum but you will know for sure when you start sanding it. Carbon fiber bikes do not have any seems on them because the pieces are glued together then sanded to hide the joints. Also, carbon bikes have more rounded joints and angles than aluminum bikes. For example, look at the area where the top and down tube are connected to the head tube. A carbon bike usually has more of a smooth curve at the angle of the top tube and down tube. Aluminum bikes have more of a sharp angle and less of a curve because the joints have to be butted in order to be welded. I posted a link on a forum topic of "How Carbon Bikes Are Make" just in case you are interested. Here is the link.

[Dalton2250]

(06-01-2011, 10:05 AM)JohnV Wrote:  If you have welds, it is most likely aluminum but you will know for sure when you start sanding it. Carbon fiber bikes do not have any seems on them because the pieces are glued together then sanded to hide the joints. Also, carbon bikes have more rounded joints and angles than aluminum bikes. For example, look at the area where the top and down tube are connected to the head tube. A carbon bike usually has more of a smooth curve at the angle of the top tube and down tube. Aluminum bikes have more of a sharp angle and less of a curve because the joints have to be butted in order to be welded. I posted a link on a forum topic of "How Carbon Bikes Are Make" just in case you are interested. Here is the link.

Ok mate, again, thanks for your help.

That link you provided was very interesting actually. I've sometimes wondered how these beasts are born!

Back to what we were saying, if it is aluminum then, which I suspect it is, what's the chemical called that can get the paint off? And is there any sanding required after or before using this chemical? And finally, what kind of sandpaper is the best to do this? I've heard there are different types & it's important to use the right one.

Cheers

Si

[JohnV]

There is a paint remover that I use on auto parts and other things that is a jelly that you brush on and let sit. It is made for removing paint on fiberglass but works well with metals, although I'm not sure if it will damage the resin in carbon fiber. I can't remember the name of it, but I can let you know when I get home as I think I still have some left. After you let it sit for a while, the jelly loosens the paint to where you just hose it off. You may need to apply a few coats to get all the paint off the bike. However, if it is aluminum, I think they have sand blasting beads especially made for it and your friend can help you there. I would use the 000 or 0000 sand paper or emery cloth to make sure that you don't gouge the metal. I would use the 0000 if the bike turns out to be carbon fiber.