# Unusual problem with Sintra PVC board



## Ray Dunakin (Jan 6, 2008)

I just encountered an unusual problem with some Sintra PVC foam board I bought back in July. I started using some of the 3mm sheets a few days ago, and had a structure partially assembled. Then it started coming apart. The glue I normally use was not adhering to it at all, which is really weird. So I tried sanding the surface, and discovered it had a super thin layer of clear vinyl or something on one side! In all the years I've been using Sintra I've never seen that before. 

I couldn't tell by looking at the sheets that there was any kind of coating, and there was nothing in the ordering or packaging info that mentioned it. But apparently it's supposed to be peeled off. 

I had some 1mm sheets in that same order, and those did not have the peel off coating. 

Anyway, I just thought I should give you guys a heads up on this potential issue.


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## Greg Elmassian (Jan 3, 2008)

Ray, clearly the new clear stuff is not easy to see, any tips on watching out for it, or detecting it? Must have been frustrating.

Does it peel off easily?

Greg - 677


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## greghile (Jun 10, 2008)

Interesting. I buy Komatex from Tap Plastics, which is supposedly the same thing as Sintra. It has always come with that thin sheet on one side, and it took me awhile for me to discover it, too. However, I just bought some 1/4 and 1/8 inch sheets and checked them. The 1/8 sheets had the sheet and the 1/4 ones did not. 

Greg, the film does come off easily. It's the same type of sheet that you find on the pink foam board from HD (and presumably the blue from Lowe's). You can tell which side is which because the side with the sheet is much smoother. At least that was the case with the latest batch.


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## MikeP (Jan 4, 2018)

I just had to delurk to reply to this thread. I started scratch building just last year after getting really into the stuff being done by ... Ray Dunakin. So off I went to the plastics dealer in nearby Ottawa for some 3 mm Sintra, only to find it didn't paint or glue like Ray said it did.

Needless to say all the 3mm Sintra I've been buying has this cellaphane like coating on it that needs to be peeled off (and can be spotted in most light if you know what to look for). I don't know about 6mm because I haven't yet bought any.

But also: thanks, Ray, for all the inspiration.


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## Scott (Jan 29, 2008)

Ray, is there the possibility of products being mixed up by the supplier? It may have happened unknowningly before the manufacturer realised.


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## choochoowilly (Oct 31, 2016)

Ray Dunakin said:


> I just encountered an unusual problem with some Sintra PVC foam board I bought back in July. I started using some of the 3mm sheets a few days ago, and had a structure partially assembled. Then it started coming apart. The glue I normally use was not adhering to it at all, which is really weird. So I tried sanding the surface, and discovered it had a super thin layer of clear vinyl or something on one side! In all the years I've been using Sintra I've never seen that before.
> 
> I couldn't tell by looking at the sheets that there was any kind of coating, and there was nothing in the ordering or packaging info that mentioned it. But apparently it's supposed to be peeled off.
> 
> ...


ray what type of glue do you use, I have read that super glue works best but I would rather believe a expert like your self? Thanks Bill


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## MikeMcL (Apr 25, 2013)

Yep, I've been using generic PVC expanded foam board for several years and there has always been one side with the peel off plastic film. 

I use "Household Goop" found everywhere. It is the same as E6000. Works great for bonding any material and is forgiving in cases where the materials bonded have mismatched thermal coefficient of expansion.


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## choochoowilly (Oct 31, 2016)

Ray, what type of glue do you recommend for Sintra board? thanks Bill


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## Ray Dunakin (Jan 6, 2008)

choochoowilly said:


> Ray, what type of glue do you recommend for Sintra board? thanks Bill


Bill, I use Weld-on 16, which is also sold under the SciGrip brand as "16 fast set" for acrylics.


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