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Building Tips and technical articles. => Building techniques => Topic started by: the original Steve Smith on February 17, 2007, 10:15:29 AM

Title: Plasticizer?
Post by: the original Steve Smith on February 17, 2007, 10:15:29 AM

I have seen the concept of plasticizer mentioned in some finishing articles and I have a few questions.

Why use plasticizer in dope?  I assume it makes the covering less brittle and more flexible.

I am planning on using silkspan on a Ringmaster - is plasticizer a good thing on silkspan covering?

I think Brodak has a product but I also recall someone using something more common but I cannot remember what it is.  It seems that a few drops was all it took.   S?P

Anyone have any experience good or bad with the concept and actual use?

Thanks,
Steve

Title: Re: Plasticizer?
Post by: RC Storick on February 17, 2007, 10:54:28 AM

Easy plasticizer is 1 drop of Castor oil per ounce of dope. Less cracking. You can also use flex-all available at the paint store for rubber bumpers.

Title: Re: Plasticizer?
Post by: Robert W on February 18, 2007, 07:37:17 AM

Is that one drop per unthinned or thinned ounce of dope? The second question would be does this also reduce the amount of shrinkage?

Title: Re: Plasticizer?
Post by: RC Storick on February 18, 2007, 07:52:40 AM

Add Castor before thinning. Yes it reduces shrinking some.

Title: Re: Plasticizer?
Post by: Jim Oliver on February 18, 2007, 08:38:39 AM

Hi,

I have used Sig Lite Coat clear and found it to have different sanding characteristics than Sig Super Coat clear.  Also, Super Coat clear with Dave Brown's "Flex All" added ( about half of what the instructions suggest) also have different sanding properities.

The Lite Coat and Super Coat with "Flex All' added wanted to roll up under the paper when I tried to dry sand them; wet sanding is OK, however.

As usual, YMMV!

Jim

Title: Re: Plasticizer?
Post by: Bill Little on February 18, 2007, 10:24:33 PM

Quote from: Jim Oliver on February 18, 2007, 08:38:39 AM

Hi,

I have used Sig Lite Coat clear and found it to have different sanding characteristics than Sig Super Coat clear.  Also, Super Coat clear with Dave Brown's "Flex All" added ( about half of what the instructions suggest) also have different sanding properities.

The Lite Coat and Super Coat with "Flex All' added wanted to roll up under the paper when I tried to dry sand them; wet sanding is OK, however.

As usual, YMMV!

Jim

Hi Jim,

The Flex All seems to extend the curing time of clear dope.  That is the rationale I came up with when i got the bubble gum bits when sanding.  it went away later when the dope had dried longer...........

Bill <><