Chassis Paint

[nmauduit]

ok thank you for the precision. I recall there was a clear version of Por-15 as well, might have an old can somewhere (been sitting for 20+ years)...

this urethane would keep some flexibility once cured, right ? that is one of the issues I have with some of the baked powder coatings out there, they are very hard at the surface and impervious with all fluids (including race hydraulic fluid) which is good - but they would delaminate under stress and corrosion would develop underneath... and it's difficult to trust the people who sell the powder coatings since they often have only one supplier and they just keep telling it's a great product for all things, but painting a cast central heating radiator and a motorcycle or Lotus chassis is not the same thing...

[Grizzly]

I couldn't tell you if there was a clear POR-15 but i know allot of Guitars use Urethane clear now a days, even some car manufactures have tried it but it's very hard to correct defects making it quite labor intensive and many don't like the finish it gives you.

Yes Urethane will flex. The thing is with Por-15 for example it's quite thin as these things go, so if it's a low contact area that has an amount of flex a POR-15 product would be great but if you want a real film thickness you would need a 2k Urethane (which is quite expensive) or an Epoxy.

[jeff jackson]

+1 for POR 15.
Without going into mind numbing detail, and being pedantic:

"Opinions are like Belly Buttons, everyone has one!"

My wife hasn't!!

Too much surgery saw to that.

Jeff 72+2

[scalino65]

rust.co.uk do a range of 2 part epoxies in various colours including RAL. I've used it and it seems ok.

[englishmaninwales]

+1 for POR 15 system.

[mikealdren]

and another for POR15. Their thinners are expensive and I found that you can clean brushes etc with acetone (I have a 5l container from fibreglass work).

[rcombs]

I used a product called Zero Rust and mixed their red oxide and red to get the color that matched what was on the chassis originally.This came out great for the color and the finish, but it is not as durable as Rust Seal, POR-15, or epoxy.

KBS Rust Seal red oxide is very close color wise, but not finish wise.

Rick

[Tmac897]

I?m in the process of painting the chassis with POR-15. Had it sandblasted first, and then the 3 step process, clean/degrease, metal prep, paint first coat, paint second coat. The 4 step process, clean, metal prep, 1st coat, 2nd coat, top coat. The 5 step process.... For all you Monty Python fans out there.

Anyway, just a couple of questions for those who have used it before:

I used gloss black, and it really gives a nice finish without a finish coat. Now they say if it?s going to be exposed to UV light, you have to put a finish coat on it. But I?m thinking if the frame is exposed to light, then something is very, very wrong! Curious to know your opinions / what you did?

What about suspension arms, transaxles, hubs, etc. What did you do there?

Best,
Tony

[Tmac897]

Jotun epoxy is good stuff, i use it a fair bit combined with Dupont Epoxy. I'm a bit of a Epoxy fan, just make sure you have the appropriate thinners to clean out your gun because if it sets it's going no where

I just think por-15 is a bit more user friendly.

Isn't Por-15 an epoxy base coating ? I have not used it in a while since it's not as easy to source in Europe than in the US, but that is what I remember of this product line...

From memory (i could be wrong) POR-15 is a moisture curing Urethane.

I believe the same company dabbles in Epoxys too but i'm fairly sure they made their name in Urethane products.

Urethane is great for chassis etc as it's hard as hell when cured and has very good chemical resistance. It also sprays really nicely when thinned with the Urethane thinners, a bit like Epoxy though make sure you have plenty of appropriate thinners handy because it will wreck your gun if not cleaned out thoroughly before it cures.

Just painted my chassis with POR-15 this pat weekend. I?m pretty happy with the results. As the gentleman above stated, POR-15 is a urethane-based paint. It can be brushed or sprayed. I brushed, and it is self leveling as claimed, but I would recommend spraying, if you can. It will probably yield a better job overall. It requires two coats, though, and a thorough cleaning of your spray gun in between, if you ever want to use it again.

Also, the mfr states that the product degrades with exposure to UV light. Since the frame is mostly covered by the body, I didn?t think a top coat would be necessary. I confirmed via a quick call to Ken at Dave Bean Eng.

If you want, I can post a few lessons learned/things to do items for you.

[The Veg]

Please do!

[Tmac897]

Please do!

Note: Not directed at you!

What, are you kidding me? I just typed for half an hour, and when I hit Submit it took me back to the login page, wherein all my hard work was lost. This sucks!

OK, now this is directed at you. I don't have time to retype the whole post again now, but I'll retype it in another text editor later tonight or tomorrow, and cut and paste into the post. Lesson learned!

Best,
Tony

[nmauduit]

I just typed for half an hour, and when I hit Submit it took me back to the login page, wherein all my hard work was lost. This sucks!

this has happened to me several times, there may be a timer logging of people after a delay (a month?) or after some forum maintenance operation... I've also wondered if that was linked to a new post being posted while the one being written as a "reply to" was not yet posted - and unfortunately backing up a page would not allow to retrieve the typed content.

[Tmac897]

OK, here goes...

1) I didn't have any way to suspend the frame, so I had to put it up on saw horses and paint it over two days. I painted the top and two sides on the first day (two coats), then after it cured overnight I turned it over and I painted the bottom (two coats). In retrospect, I probably should have painted the bottom first, since that's the only visible section of the frame -- visible being a relative term in this case. The paint is made to be self leveling and it's a little runny, so some of it ran onto the section I wasn't painting, and left some splotches. But I don't expect too many people crawling under the car except me, so I wasn't too bent out of shape. Professionals suspend the items to be painted, but I don't have an engine lift, or the room to suspend it from wires on the ceiling, so I did the best I could.

2) POR-15 dries very hard, and sticks to everything to which it comes in contact. I didn't want it to stick to the saw horses, or even leave marks where the two surfaces met. You could theoretically be very careful around the mating surfaces. Even though the paint looks pretty thick, it's actually pretty runny (obviously one of the mysteries of life), so I thought that an iffy proposition. I put wooden shims between the frame and the horses. What's the difference you say? Well I used very narrow shims, and oriented them parallel to the frame, and (almost) perpendicular to the horse crossbars. The shims were also narrow enough that they were completely concealed underneath the frame, and away from the frame edges. Even with all this preparation, some paint got on one of the shims and it stuck to the frame in one spot. But it wasn?t much and I sanded off the splinter after I pulled the shim off.

3) The instructions call for two thin coats to be applied. You have to apply the second coat between the time it's "dry enough," and when it's fully cured. Otherwise it will be necessary to sand it between coats. I hate sanding? That puts you somewhere between 1 and 3 hours. Be careful, because heat and moisture aid the curing process. I live on the water, and it's always humid here in the summer. Plus last weekend was pretty hot. Mine was ready to recoat in about an hour. There's a test to see when it's ready: Touch your fingertip to the surface. If any paint comes off on your finger (See #5!) it's still too wet. If your fingertip is dry, then drag it along the surface. You should feel some slight resistance, like it was still a little tacky. If you have those two conditions, it's ready to recoat.

4) Use a disposable, but good quality brush (not polyethylene though!) if you're brushing. Don't use those little disposable brushes from Home Depot or the other big box stores. They shed bristles like it's their job. I didn't get them all out. So use a better quality brush that doesn't shed as much. Disposable, though, 'cause you're not getting that brush clean, even between coats, so have at least four brushes on hand. Maybe an extra or two, if you think you're going to drop one?

5) Wear gloves, a long sleeve shirt you're not attached to, long pants, and a hat -- basically a DIY Hazmat suit. If you get any of it on yourself, wipe it off quickly or you will be sporting a blotchy tattoo for several days, until it wears off. Might be fun figuring out what you see in the blotch?

6) Wear a respirator, even if you're brushing. The stuff gives off some fumes! I wore safety glasses, too, even though I wasn't getting too far underneath the frame. If you're suspending and painting the underneath parts, you don't want this stuff in your eye.

7) Drop cloths are a must, unless you're going to be nostalgic about your paintjob and want little reminders all over your garage floor. I painted inside. I live in the place where wind was invented, and I didn't want random debris and greenhead flies sticking to my finish. If you live in a friendlier painting environment, paint outside. It dries fast enough.

Don?t paint from the can. Air and moisture are your enemies in this case. Plus, you'll get the rim all full of paint, and the lid and can will become one inseparable unit. Some people put a small hole in the top of the can, pour out what they need, and then seal up the can with a sheet metal screw. I poured the whole can into a Mason Jar with a screw top, and then poured what I thought I needed back into the can and painted from there. I know, I just said not to do that. But I never intended to keep the unused paint in the can, and I was intending to throw the can out after. The Mason Jar worked out well. I was able to pour out just what I needed, and the rim is easy to wipe clean. I used about half of the quart can for two coats on the hole frame. The unused paint was kept airtight in the jar, and is available for other parts of the project. The stuff is expensive, and I'm cheap.

9) I was pretty careful not to paint any threads, like the A-Arm studs in the front of the frame. I also tried to get as little as possible into the threaded holes in the frame. Not sure how much it matters, but the stuff dries really hard, and I didn't want to have to re-tap all the screw holes. It remains to be seen if I was successful.

That's about all I can think of now. Hope it's helpful. If you have any other questions, don?t hesitate to ask.

Good luck!
Tony

[The Veg]

Thank you Tony, that is helpful!

And you have my sympathies regarding uncommanded logouts and lost work. I've had a few logouts from this site happen when navigating about after minimal time on a page, so something might be screwy.

[mikealdren]

Agree with all above. POR15 thinners are V. expensive, I found acetone (cheap by 5 litres) that I use for fibreglass work cleans it off easily.