I'm getting ready to order some SEM Landau Black (#15013) to paint a few of the beige interior trim pieces that may take awhile to find original black ones of: door window trims, one back seat window trim, and possibly the center console and/or stereo/shifter surround.

First question is, how many cans is that likely to take? I have three in my cart at the moment.

Second, is there a consensus on what steps to follow and which products to use? I've read a couple dozen threads and am less certain than when I started... Most of the info seems to pertain to leather (seats and steering wheel), so I'm not exactly sure what to make of the vinyl surfaces.

SEM Soap (#39362?)
Plastic/Leather Prep (#38353)?
Adhesion Promoter (#39863)?

The SEM Soap is commonly recommended as the first step, but then there are those who say a mild soap mixed with degreaser is the same thing. I imagine dirt and grease doesn't penetrate vinyl like it does leather.

The Plastic/Leather Prep is similar to the Soap, being commonly recommended but also replaceable by acetone/thinner, possibly diluted 5-10%. Seeing as I'm not doing plastic or leather, I'm unsure if it'll be of any benefit.

Likewise, Plastic Adhesion Promoter is frequently recommended, but the people who have used it on some parts but not others don't seem to report an effective difference. Plastic is one of the tougher materials for paint to stick to, so it makes sense that it would benefit from an adhesion promoter. The product name makes me think it would be a waste of time on softer surfaces.

Is sanding after cleaning recommended on vinyl, as with leather, or just scuff with a grey or green scouring pad? (Combining lots of suggestions here!)

My understanding is that a clear top coat is not recommended.

 

Let me simplify your life a little and refer you to the TDS (technical data sheet). When in doubt always follow manufacturer recommendation (this is a key to ANY refinishing).
http://www.semproducts.com/manage/ht...color_coat.pdf

Here's another PDF they have about plastics:
http://www.semproducts.com/manage/ht...g%20Manual.pdf

I would personally use it as a complete system. As far as how much you need, I'd assume 2-3 cans is sufficient. Again just read and follow the tech sheet. Everything is there.

 

Point taken, but the manufacturer recommendations are always going to be to use their line of products, whether or not it matters. The tech sheet does clarify some of the inconsistencies (what to or not to use together) reported in the product lineup, though. And it adds a nice tip about water beading up as the indicator of prep completion.

The tech sheet says to use SEM Soap followed by Vinyl Prep (#38343). That's the first I had heard of the latter, so scratch Plastic/Leather Prep from the list.

Thanks. Sounds like I was in the right ballpark.

 

They recommend their product because they know the chemistry behind them.

 

That makes sense for primers and topcoats, but generic cleaning steps shouldn't leave anything behind that would affect the paint chemistry.

 

Just one of many examples:

http://www.bimmerforums.com/forum/sh...-SEM-Vinyl-Dye

All in one place, you've got pros saying to not bother with SEM's prep products, and recommendations to use adhesion promoter (also found here in CL threads) on vinyl.

 

They shouldn't, but often times they can. Quickly looking over their products the soap is a mild abrasive as well as a cleaner, and the vinyl prep is an adhesion promoter specifically formulated for vinyl. Again I see no reason not to use it as a system...

Side note - Their soap TDS mentions not to rinse with water for vinyl or leather:
http://www.semproducts.com/manage/ht...s_sem_soap.pdf

 

Here you go get all of this...

Use the prep spray first....and clean the parts off with it....

Then Spray Color Coat...


It needs to be pretty warm out and I would spray it in full sun.....also if there is humidity in the air the top coat will not adhere good enough to the parts and will peal off easily.

 

Cover wood trim and spray everything while it's in the car! Just kidding, terrible idea, but that's how I did my dash. I just put a piece of cardboard on the inside windshield and sprayed away. Came out great and that was several years back. I cleaned the dashboard really well with alcohol and it came out perfect.

 

CatMan, that's just 3 products, right? I can't make out the Color Coat details, but I assume they're all the same thing. That would mean your recommendation is just one prep product for vinyl and one for plastic/leather? I.e., no SEM Soap?

See what I mean about no consensus?

I won't be painting the dash, as I swapped in an original black one this past week. The pieces I need to paint are just the trims mentioned in the first post, all of which will be easy to remove and require minimal masking.

Tabaka, did you use any of the prep steps in addition to the alcohol? The more I read, the more convinced I am that the SEM line of prep products is for convenience and peace of mind only.

Low humidity is a challenge around here, even when the temperature is in the 70 degree target range...

I've actually almost talked myself into giving the DupliColor a try after that Bimmer Forums thread. I've read more since that and surprisingly, there's no clear cut preference between DupliColor and SEM for vinyl/leather. But, DupliColor is less than half the cost and, most importantly, stocked by all the auto parts stores so I don't have to guess at how much to order.

 

Everything you need is in the data sheets... As a painter I've given you exactly what I would utilize if I were to do this job. I feel like you are convinced of something else already, so I'm not going to attempt giving you advice from here. Good luck with the process though.

 

I'm not saying that won't work. I'm saying I'm skeptical that it works any better than alternative methods recommended by many. I was on the fence about that at the start of the thread.

 

i simply cleaned with rubbing alcohol and painted right in the sun at least 65F outside, otherwise nothing will stick, turn grey, and peel off.

 

^ Now that's one thing that's definitely a consensus. 70 degrees if you want it to stick.

 

I went by AutoZone to see if the DupliColor Gloss Black (HVP104) or Flat Black (HVP106) looks good in person. The Flat is way too flat, but I brought along the leftmost dash trim piece (the one that pops off easily below the vent) and the Gloss looks like it'll work great.

I also wanted to read over DupliColor's instructions, as nowhere had I seen people recommending specific prep steps for it like with SEM. Sure enough, there are none. Just clean thoroughly.

As a bonus, it's on an unadvertised special currently. The local store only had one can left on the shelf, so they ordered a couple more for me from another store. It'll be a few days before the weather is cooperative for painting, anyway.

If this works out, the cost savings are significant. We're talking less than $20 for three cans as compared to $85 for that amount of SEM and the prep products. (Or just $45-50 for the SEM paint + generic prep steps.)