Where to get Carbon bike parts re clear coated

[PPWTF]

I've got a Truvativ carbon crank that's started looking pretty scruffy, the decals  have started rubbing off stuff after just a few rides, so I wanted to know if there is anywhere that does work on carbon bike parts.

 

My thinking was I'd get new decals made up / bought and have a top layer applied over the decals... not exactly rocket science, and to be honest I'm staggered that the manufacturers don't do this themselves on gear costing this much...

 

Any advice is much appreciated

 

[Johan Bornman]

You can buy surprisingly good clear lacquer in spray cans. Use sandpaper to remove the old stuff and spray it. If you don't like the look or you've made some drips, sand it again and try again. The experiment will cost you all of R36-00

[AndreZA]

As JB says. Just roughen up the ols surface with fin sandpaper and spray with a can of good spraypaint. Don't do and get the R10 can at P'nP. Spend some money. Or if you have to go to a panelbeater and ask then to do just the outside then next time they spray clear coat. Shouls only take 2 light passings.

 

OR sand it with 2400 water paper and keep it MATT.

 

 

[R2S2]

Mmm, I see your problem is actually with the decals only, and that you want to have the clearcoat applied over the decals...

 

This is a big no-no, for regular stick-on decals, and can really only be done on water-transfer type decals.  If you try to apply clearcoat over "stick-ons" one of two things will happen:  

The clearcoat will pull to the edged of the decal, creating really nasty ridges and runs

The solvents contained in the clearcoat will phyically damage the decal.

The best you can do (unless you can get original water transfers from the manufacturer) is to carefully remove the old ones, re-smooth the clearcoat with 2000gr wet sandpaper, buff it up with a polishing compound, and re-apply stick-on decals.

 

If you still want to re-coat the components, I agree with Mampara, and would definitely not use rattle-can clearcoat.  The reasons are as follows:

It doesn't dry to as hard a coating as automotive clearcoats, and will peal off/wear through in very little time, especially on a crank.

The rattle can stuff contains a couple of very nasty solvents not found in automotive paints, that may (will) structurally weaken the carbon fibre components.

Cheers!

[AndreZA]

R2S2, I'm sprayed hundreds of littres of automotive clear coat over cut out decals. The trick is to find the best possible make. the better the quality, the thinner they are. The best thing will be to have them printed. Then your first coat of clear is a very thin mist. Let it get tacky. Then a second and a third. Let it dry for a few hours but not completely. You still want the next layer to "bite" into it. then you give another nice coat. Let it dry completely. Now you can sand it down to make the paint the same level as the decals. then you can give it the final clear coat. Sand it again with wet paper and give it a nice polish.

 

 

[TokenFreak]

I use vinyl stencils and an airbrush for the actual branding and then 2k clearcoat over that. Give me a PM if you need help

[R2S2]

Mampara,

 

Your approach sounds good to me; maybe I was to hasty in the past then!  Will experiment a bit at some stage, on something I don't mind ruining by accident!

 

Token,

 

I like your idea!  Wish I could wield an airbrush with authority!

[Johan Bornman]

 

Cut cut cut.

The rattle can stuff contains a couple of very nasty solvents not found in automotive paints' date=' that may (will) structurally weaken the carbon fibre components.

[/quote']

Aan nee. Not the dreaded FUD again.

What are those nasty solvents and how do they differ from automotive solvents?

What makes you think your inert automotive solvents were used in the first place.

Explain how a spayed on layer will affect the structural integrity.

 

Here's a challenge for you. Take one of those carbon water bottle holders. Soak it for a week in any one of the abovementioned nasty solvents.

 

Come tell us if it somehow affected the resin or the fibre.

 

Take nice photos and post them here.

 

This myth has two prongs of untruth.

 

1) A thin layer of solvent can deep-penetrate anything from aluminium to plastic. I wonder why even paint remover only works on the top layer?

 

2) The solvent in paint will dissolve the resin right out of the crank and leave you with a pap structure of fibres only.

 

 

 

 

[madmarc]

popcorn anyone!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[TokenFreak]

so i guess none of the carbon bikes or parts on the market are clearlcoated after branding has been done on them?? 

[R2S2]

Let's answer Token first. <?: prefix = o ns = "urn:schemas-microsoft-com:office:office" />

 

Generally the decals used in applications where paint is applied over them is not the traditional stick-on type that you have made at your nearest vinyl shop.

 

I have quite a bit of experience in spray-painting, and the fact is that, ?till very recently the practice was to use water transfer decals if you wanted to paint over them.  However, having said that, I can only speak from my own experience, which is limited to one or two occasions over the last 17 years, so I am very happy to accept from Mampara's and your own experience that it is possible to paint over stick on decals if they are of the right type, and you have time, and you know what you are doing.

 

As I said, I will actually give it a go at some point, as my airbrush and stencil skills are non-existent.

 

As I have now had the time to count to ten, let me turn my attention to to Johan (and my sincerest apologies to all for the thread hijack here!):

 

You don't really like to hear that not everyone agrees with you heh?

 

Just for the record of other hubbers that may be reading here, may I point out that your snide remark towards "rocket scientists" in a previous thread (chain stretching) was directly aimed at me, even though I didn?t even take part in that particular discussion.  This back-handed swipe followed from a private disagreement we had regarding the basic laws of physics.

 

I especially considered the "rocket scientist" remark as a bit of a low blow, as I at least had the decency and ethics to significantly differ from you in private.  I believed then, as I do now, that you add a lot of value here, and I agree with most everything you say.  For this reason I didn't want to detract from the good that you do, by picking at a perceived gap in your understanding, nor by responding publicly in any way to your underhanded tactics.

 

Not that I originally mailed you and called you an idiot - I think my mail was sent in a well mannered and good natured way.  Then too you got all curt and snotty the moment someone dared to differ from you and your last private mail, sighting lack of time for arguments, proved that you simply hate being wrong.

 

I guess it isn't always easy for us humans to come to grips with the fact that we sometimes get answers wrong.  I do however hope my response in this thread to Token and Mampara's challenges to my understanding has then at least proven that you and I differ in this one crucial way:

 

I accept that others may know more stuff than I do, and will publicly admit to that.  You don?t and won?t.

 

Having gotten that off my chest then, here follows paint chemistry 101 (backed up by my good friends at Advanced Material Technologies, Glasurit and Plascon, who again know more than I do):

 

Automotive paints are generally epoxy based two part concoctions these days, typically consisting of 50% paint, 50% hardener or catalyst, and an optional small quantity of a volatile component or thinner. (This volatile component is -and I really don't know if the spelling is correct- a chemical called polyacrisane.) 

 

The volatile component content is very low, and hence flashover times extremely short. This is because modern HVLP equipment allows for very fine atomization, hence a smooth enough application that extended flow time is no longer a prerequisite for a glossy finish.  Full hardening after flashover is actually a function of a chemical reaction between the catalyst and the epoxy based paint, and not of the evaporation of the solvent.

 

Traditional solvent based paints (like the stuff in rattle cans), usually contain very high levels of solvents ? it can be as high as 50% by volume.  This is because hardening is purely a function of the rate at which these evaporate from the paint, and if you add too little volatile contents, you get a bad surface finish, as the paint does not have enough time to flow before it hardens.

 

In order to provide for a smooth finish, you will also find that the solvents do not evaporate off at a very fast rate (longer flashover times), allowing for the paint to "flow".  Due to this, there is also a longer period for the solvents to react with whatever the base is onto which the paint is applied.

 

This is not a problem in itself, except that in the case non-epoxy paints (such as rattle cans), the solvent has an acetone base, and as you may know, acetone is one of only a few compounds that removes epoxy (fibreglass/carbon fibre resin) from anything.  Pure acetone itself is no longer used, as it is carcinogenic, but the stuff used has exactly the same solvent properties.

 

So then the answer to your challenges:

 

"What are those nasty solvents and how do they differ from automotive solvents?"

 

Acetone-based solvents.

 

Fact is that automotive based solvents as used with epoxies contain nothing that even remotely behaves like acetone, or traditional thinners.  The solvent in automotive paints is polyacrisane, and that in rattle cans or ?laquer paints? (including Duco, QD enamel etc.) is a variant of acetone.  Polyacrisane does not attack the polymer chains in resin, acetone eats it for breakfast.

 

"What makes you think your inert automotive solvents were used in the first place."

 

Because Truvative are known for the vast quantities of clearcoat rattlecans they buy.  Not?  Oh, I guess then it is safe to assume that they use proper modern production techniques which will see them use an epoxy based paint system.  Not only from a common sense perspective, but perhaps also from the fact that their local environmental agency will definitely be very happy if they were to use acetone based solvents in large quantities!

 

It might of course be that they didn't even paint the components, because if moulds are of high quality the final product will be perfect in any case, and won?t need any paint?

 

Speaking of environmental agencies; the latest trend is for automotive paints to be water based, and not to be sprayed on with compressed air, but rather splattered on using nozzles that rotate at high speeds, so as to further reduce pollution.

 

"Explain how a spayed on layer will affect the structural integrity."

 

Because the acetone based solvents in the paint will penetrate the structural component, and structural integrity is based on how far a solvent will penetrate the composite before it has had enough time to evaporate.

 

OK, so I don't know by how much it will penetrate.  It might be 0.1mm, it might be 0.2mm.  Hell it might even be 1cm.  The fact is that I don't know how far exactly, and neither do you.  If you want to wear your pseudo scientific hat, then I suggest we ignore it completely.  So let?s tell people to go buy a rattle can, and risk ing op some poor hubber's cycling components all for the sake of your fragile ego.

[TokenFreak]

There is no ego involved here on my side. I am a qualified spraypainter by trade and have worked on many bicycles frames over the last couple of years.And believe me that branding is painted on. (Some shop(wont name names) sells bicycles with paper decals sprayed over with clearcoat). I was merely giving my opinion. I have also used the water transfer decals on some bikes aswell as vinyl decals (that i make myself as i also do signage) but of all the types of recon jobs the airbrush method with vinal stencils work the best. The paint can not penetrate the frame that is why the surface needs to be scuffed for the paint to stick. If that was not the case and the paint DID penetrate the frame WHY will the paint then flake or peel if it hasnt been scuffed. To reffer back to Johan's comment about soaking the part in solvents, that is not a good idea because through the whole process of respraying a frame is it at all subjected to such an environment such as soaking or paint stripper!!!! That would be just dumb!! Go so a test on your car and leave a thinners soaked rag on it over night and see what the result would be in the morning!!!! Wouldnt advise this tho neither soaking your bike. 

[Johan Bornman]

Oh dear. I've upset someone again.

 

I'm sorry.

 

I honestly didn't mean to insult any rocket scientists when I said that something isn't rocket science or that it doesn't require a rocket scientists to see this or that. I've always considered it a generic adage that wasn't meant to harm anybody. I probably use that adage too often and should find another one. Perhaps now that blacksmiths are extinct I could pick on them in the hope that I don't offent a surviving smithie.

 

I'm also not very good at remembering nicknames, so if we've had a conversation in the past and you chose to remain anonymous, apologies if I didn't put 2 and 2 toegether. Now that you've again reminded me that you are indeed a rocket scientists, I do remember that we've kinda met before. I don't remember the spat though, I quickly forget.

 

Nevertheless, back to carbon fibre matrix and solvents. Tomorrow I'm going to soak my carbon fibre fishing rod in acetone. I'll let you all know what happens.

 

Gotta go now, someone in the household is already looking for her nail varnish remover....

 

[TokenFreak]

Sarcasm is really a great thing hahahaha

[GT_Zaskar]

Get a room or grow up and have your tiffs somewhere else.

[R2S2]

Token,

 

 

 

I at no point questioned your ego, and for the record really appreciate your contribution here. You obviously have more knowledge and experience on the subject than I (or most here) do and I am quite happy to have taken your knowledge on board .

 

 

 

My "beef" is nct with you, but rather with the way and tone with which JB seems to want to enforce his position as "uber expert" that lead to my previous response.

 

 

 

My sincerest apologies if you felt that any of my ccmments were aimed at you, as that was certainly not my intention!