| Author | Message | ||
     Hughlysses |
This is my second full paint job on my Uly muffler. I did a pretty thorough repaint about 5 years ago but the paint had blistered and the muffler was VERY rusty in all the areas that get very hot. After seeing what the muffler looked like in a professional photo (Blind Kenny on NC Highway 80 / "the Devil's Whip" / Buck Creek Road) I figured it was time to do something:  For the previous paint job, I'd used wire wheels, Scotchbrite wheels, sandpaper, etc. until I could get it as clean as possible. This time, after doing all that, I used a friend's sandblasting cabinet and tried to get it down to "white metal". The muffler would just fit in the cabinet and there was very little room to maneuver it, and it took a good 2 hours to blast it. I still didn't have it quite to white metal in the rustiest areas. I had originally planned to have it ceramic coated locally. One shop said they had a 60 day backlog. The other shop blew me off saying they couldn't guarantee their product would stand the heat. I contacted Jet Hot and they quoted me $170 + $45 shipping, which means it was going to cost me ~$260 to have it coated by them. I just couldn't see spending $260 on an 8 year old rusty muffler, so I was faced with doing it myself. I had used Duplicolor on the previous job which gave a nice satin finish and has a fairly simple curing procedure. Apparently Duplicator is NLA so I narrowed it down to Rustoleum high heat or VHT Flameproof. Both of these paints have a compatible primer which seemed like a good idea to me. The VHT paint gives a flat finish, but they also have a spray satin finish that can be sprayed over it, so I went with that. Since some of the rustiest areas on the muffler weren't quite down to white metal, I treated them with rust converter stuff. I then sprayed the muffler down with brake cleaner and wiped it thoroughly, trying to get the cleanest surface I could get. 2 coats of gray primer with ~20 minutes between the coats, then 2 light coats of black and one medium heavy coat of black. Wait 30 minutes and then 2 coats of satin clear. This process went pretty smoothly apart from one minor glitch. The first coat of black sort of "crazed" when it hit the primer, cracking into irregular blocks in a few areas. I waited a little longer on the 2nd coat of paint and it seemed to go OK and mostly cover up the crazing. For curing off the vehicle, VHT says cure at 250 degrees F for 30 minutes, then wait 30 minutes, 400 degrees F for 30 minutes, then wait 30 minutes, then 650 degrees F for 30 minutes and wait 30 minutes. For curing on the vehicle, they say idle for 10 minutes, then rest 30 minutes, idle for 20 minutes, then rest 30 minutes, then ride normally for 30 minutes. As I don't have anything big enough to hold the muffler (besides the fact I wouldn't want to stink up the house), I used sort of a hybrid procedure. I stuck a digital thermometer in the inlet and put a heat gun in the outlet. I ran the heat gun until the outlet temp reached 250 deg. F, then I'd blow the gun around on the outside of the muffler until the outlet temp dropped to about 245. I tried to keep this going for 30 minutes. I waited a day and mounted the muffler on the bike, and then went through their complete on-vehicle recommended cure. The appearance is not great but acceptable. The finish seems a bit rough, but hopefully it's going to be durable.    I'll try to remember to post a follow-up report after a few weeks and say how the paint is holding up. | ||
| Electraglider_1997 |
Looks like you did a fine job. Would have been great if these cans would have been stainless from the gitgo. | ||
| Hughlysses |
Yea, that would have been nice. Even Jet Hot coating or similar from the factory would have been a big improvement. | ||
| Electraglider_1997 |
Mine needs painting also. I'll bet you reused the straps. All mine are originals with no failures. I just tighten until I feel resistance and then just a bit more. No torque wrench, just by feel. | ||
| Hughlysses |
Yea, I reused them all this time. I was careful to orient them just like they were originally (I believe Al Lighton said they are usually OK if you do that) and I did torque mine. That's the only downside of the "on the bike" paint cure. The paint softens under heat and you can see where the straps have sort of sunk into the paint after the last heat cycle. As long as the paint is durable, I'm OK with that. | ||
| Etennuly |
Hi Hugh. I have had a bit of experience with painting high temperature paints. For as hot as the Uly's muffler gets I have not seen any reason to be happy with doing it. The mild sand blasting is the best way to get a good clean, bare, new like, surface. From there it is all a crap shoot. I have found that primers and any extra coatings will be more material build up to burn off, usually more easily. I also see this a lot in being a welder who frequents rebuilding painted and coated truck bumpers, frames, and hitches. What I have seen hold up the best are the thinnest coats of heat proof paints. Problem is they are quite thin and easy to see through so it takes a lot of coats to build up enough thickness for coverage, then it is back to the thicker easy failure condition. I have yet to really paint mine. I have touched it up a few times with a light coat of satin black header paint. I tried BBQ grille paint but that went to ugly fuzzy flat black that looked awful. Now at 62,000 miles it looks like the air in Pittsburgh did in the 1960's. IMHO the best thing for it is to learn proper masking techniques, leave the muffler on, and just touch it up from time to time with minimal coatings of the satin black header paint. I would not even sand the surface, just make sure there are no oils or dirt on it. If the rust is fuzzy surface rust the header paint will stick well. If you have rust scabs or scale then it needs to be done more like what you did. It is a "shoulda been made of stainless" program for sure. But then.....ten years and mine is in pretty good shape for the condition it is in. I have seen some Uly's run in road salt that their mufflers were rusted through in the first year or two of service. I have been working on getting a yellow header paint to look good and stay good on my Corvette's side pipes. It took eight coats of color over two days to get coverage and it got soft everytime they got hot the first couple of months. Now almost a year later they still scratch easy when hot and they have taken on stains from road dirt. So this is simply another case of keep a can on hand and touch it up before showing anywhere. | ||
| Electraglider_1997 |
I remember when everyone was getting new mufflers under warranty. Nothing changed except that you got a new muffler and it cost Buell a fortune for all the warranty work. I suppose it was the accountants fault but also just another nail in Buell's coffin. Full disclosure is that I got a warranty muffler. I also asked to buy the muffler they were taking off but it wasn't allowed. Imagine it ended up in the dumpster, what a shame if that was the case. Can't imagine they spent any money shipping those heavy mothers anywhere. | ||
| Ourdee |
Any thoughts on POR-15? http://www.por15.com/HIGH-TEMP_p_104.html Any thoughts on another color besides black? I figure on hitting mine over the winter.  | ||
| Hughlysses |
Vern, I'm really interested to see how this stuff holds up. I'm hoping the extra prep I did this time makes the difference. I did think about getting POR-15 but there is only one retailer locally and they're 20 miles from me, plus I already had a can of the VHT black. The VHT Flameproof actually comes in several colors if you want to try something other than black. | ||
| Ourdee |
The POR-15 high heat paint, I think they called it POR-20 at one time, comes in black, grey, and aluminum. My goofy thinking was to paint it red with a cherry bomb logo on it. I don't know any more. When I change something on a Buell, I wind up putting it back to stock after a while.  The logo doesn't look all that good. | ||
| Timbobuell |
Por 15 black velvet bvh. 20.62 free shipping Amazon. Pulled mine and painted 2 years ago. Wear gloves, and use in a well ventilated area. Surprised the epa allows such great stuff to exist... Simply works. | ||
| Etennuly |
Hugh it will be interesting to see how it does over the next few rides. I have not tried the Por 15. I will look into it. I am also going to try(I think the brand is) VHT's brake caliper paint. They have it in multiple colors including yellow. I'd like to have it on my Vette pipes to closer match the two tone yellow paint. It has got to be tough to resist the heat of the calipers I see it on at the autocross rallys. They come in after a couple of laps just smoking hot and looking good. | ||
| Hughlysses |
I wonder what it'd cost to get the muffler hot-dip galvanized? I imagine the main problem with that would be the muffler valve; I can't imagine any way you could prevent that from being "welded" into position by the zinc. Otherwise, that might be the ideal coating. | ||
| Etennuly |
I have welded a lot of galvanized metals, it does burn back a bit. I see a problem with galvanized coatings being fumes that it can release when heated enough(that shit can kill ya), and it can cause corrosion of the steel it is protecting when water can get trapped between it and dissimilar metals, like the mounting straps or the upper aluminum brackets. | ||
| Hughlysses |
I was just thinking most car exhausts used to be zinc-coated and it held up pretty well. Seems like most if not all car exhausts are stainless steel now. I think zinc is OK at normal exhaust system temperatures but like you say it makes nasty fumes when you try to weld on something that's galvanized. Like you say, bi-metallic corrosion might be a concern. I think the straps would be OK- stainless is more "noble" than zinc (that means the zinc dissolves while the stainless is OK) but the aluminum mounts might be a problem. I just figure with our mufflers, the molten zinc would run down into the muffler valve mechanism when they're dipping the muffler and then solidify, freezing the valve in the closed position. That wouldn't be a problem for an XB9 at least, but it would be bad for a stock XB12 muffler. (Message edited by Hughlysses on September 08, 2015) | ||
| Etennuly |
The bi metallic corrosion of what I mentioned was increased corrosion of the muffler itself in the areas that the other parts are touching it. Water, when trapped against galvanized surfaces will turn it into an acid. For the last twenty years or more manufactures have been using an aluminized coating on auto exhausts. I have no idea if that would work, and at this time I don't know the processes to install it. I'm sure it would be better than zinc. | ||
| Etennuly |
The aluminum coatings on exhaust pipes does NOT burn back from welding, that is a good sign of what it will tolerate. | ||
| Hughlysses |
The whole purpose in galvanizing is for the zinc to corrode away rather than the metal it's coated on. I know some effects can occur like you're talking about but they still use zinc sacrificial anodes on ship hulls, in water heaters, etc. and they make galvanized hardware for marine environments. At any rate, I don't think any of us are going to zinc coat our mufflers. The aluminized coating might be the way to go. They can flame-spray aluminum powder onto metal surfaces. I read up on the process about 20 years ago for a Navy project. They actually do this on anchor chains and in anchor chain rooms (the room where all the hundreds of feet of anchor chain pile up when they retract the anchors) on ships. The spray gun is sort of like an oxy-actylene torch with a gizmo that drops finely ground aluminum into the flame. It gets blown onto the surface and solidifies. There are apparently a huge number of variations on this process: https://en.wikipedia.org/wiki/Thermal_spraying A spray aluminum coating might actually work with an XB12 muffler, and you could probably keep it out of the valve so it would still work. | ||
| Smorris |
how is the POR-15/20 holding up? | ||
| Twotalltodd |
I pulled mine and had it ceramic coated, it started rusting after a little over a year. The guy redid it with a special 3 step process I asked him what it was as it's absolutely beautiful and he said it was; Cerma chrome coat then full cure and polish , blast and a c-7600 glacier black ceramic coat. He said it will handle the heat and the wet. I have not had the chance to test the later since I live in california. What I have her dynoed I am gonna have him do the pipes. I hope this helps | ||
| Etennuly |
How is it holding up Hugh????  |
