280z Interior Plastic Repair and SEM coat

[ckurtz2]

Hey guys,

       I am repairing the interior trim on my 280z and I wanted your advice on what I should do. I have read forums everywhere, and it seems like everyone has a little bit of a different method. My panels aren't terrible, but definetly need some structural work. I took some photos of the cracks, but there are a lot more. I was wondering if I should just tack glue things back together with superglue then put plastic epoxy over the back? Others say they add a little bit of fiberglass too? I could do that, but would I need epoxy resin for that too instead of the plastic epoxy. In addition, how would you repair those cracked holes where the pop clips should go through.

The thing I am most confused about though is how to paint them with SEM products. I bought the SEM plastic adhesion promoter, and plastic/leather prep, and then a white colorcoat. I have now read there is a product called SEM sand free that people also use to prep the plastic? I am confused as to if I should use the sand free or adhesion promoter. If there are any SEM masters in here please share the best way to go about this, I really want to get this right the first time and never have to touch these again. I am looking for the original plastic texture to look the same. I provided some photos of the affected areas. Thank you!

 

Edited December 6, 2022 by ckurtz2

[DatsunZGuy]

I have achieved good result using JB Weld Plastic Bonder and reinforcing the back of the panels with sections of window screen to strengthen the area and provide a good base to fill any voids.  

 

[ckurtz2]

@DatsunZGuy

Did you put the epoxy and screen over the whole panel. or just the areas that had cracked?

 

[DatsunZGuy]

@ckurtz2 I applied the JB Weld and screen material just to the areas around the cracks or voids.  I went so far as to also reinforce the rivet areas as well.  Any excess epoxy or screen was removed with an xacto knife and light sanding with my dremel tool.

[Patcon]

I would see if you can reach out to SEM directly. Many of these suppliers have a way to ask technical questions. Or talk to a local auto paint supply house near you

[zKars]

Done plenty of all of this. SEM Plastic Prep (not vinyl prep) works wonderfully, It’s primary job is to clean and degrease to remove traces of everything un-desirable. Then use an adhesion promoter like SEM 39863 JUST before spraying the top coat. This softens the plastic and let the top coat stick. 

Franky anything that will thoroughly degrease the plastic and clean it without leaving any residue will work. I’ve recently been using generic body shop degreaser to clean, even Spray 9, anything powerful and degreaser-y. Then Adhesion promoter, THEN top coat. 

The Sand Free product sounds like a newer development for coloring plastics. I haven’t used it, but the description sounds interesting. PLASTICS only.

Vinyl and leather dying is different. The Vinyl preps typically clean and degrease and do the adhesion promotion all at once. Filthy vinyl, use spray 9 and a scrub brush and water rinse, THEN  vinyl prep just before top coat.

Cannot stress enough the need to clean the plastic or vinyl extremely well. None of the top coats stick to 30 years of sweat, body oil and Armor-All worth a damn. Big surprise. I’ve even used Scotch brite pads to scrub to get whatever off da plastic first. 

Hope that helps

Edited December 8, 2022 by zKars

[ckurtz2]

@zKars

This clears up a lot of confusion, and makes me feel confident I bought the right products for the plastic. In regards to the vinyl, do I need to buy the SEM vinyl prep, or can I just use their plastic prep? Otherwise, you answered all my questions:) Thanks

[zKars]

Don’t interchange the vinyl and plastic preps. They are different. 

You’re welcome

 

[Randall.K12]

On 12/6/2022 at 10:31 AM, DatsunZGuy said:

I have achieved good result using JB Weld Plastic Bonder and reinforcing the back of the panels with sections of window screen to strengthen the area and provide a good base to fill any voids.  

 

Thank you for this post.  Swapped the screen for fiberglass cloth and treated it more like a layup, but I used this epoxy to bond everything.  I'm happy with the results I'm getting.