Cracked it, PU white primer, top coat acrylic

[tracyreed]

vB_ID:3332

pu acrylic.jpg (86.58 KiB) Viewed 1 time

[ArferMo]

Nice rich colours well done. What was the substrate underneath it all this time.

I quite like the original artwork too.

[tracyreed]

Hi its MDF, 2 coats of white pu primer, and a wetlook acrylic coating. Not my artwork though, pinched of google so I could check the colour vibrancy.

[Greybeard]

Stupid question alert !
I take that the transfer was pressed onto the white pu primer, then after printing, sealed with the wetlook acrylic coating ?
Thanks for sharing,

John

[tracyreed]

Hi Greybeard no, two coats of primer, then the acrylic then press

[pisquee]

Have you costed this out Tracy in terms of per square cm and in terms of time/labour?

[tracyreed]

Hi Pisque, yep done the costings and works out very cheap compared to the dyesub coatings, around £14.50 per litre for usable product, the spraying of a 8ft piece of mdf takes literally mins. We do have a spray booth though.

[Greybeard]

Hi Tracy, and thanks.
You've now got me puzzled though, trying to get my head round the chemistry. Being very new to the business, I thought that dye sub was 'best' done on pu surfaces, yet you're putting an acrylic on top of the pu.
Or is it an 'acrylic pu' coating ? I know a lot pu varnishes are made water miscible by changing their chemistry this way.

Perhaps I worry too much !

Regards
John

[tracyreed]

no its an acrylic wetlook top coating, lol, dont ask me to explain the chemistry, Im a girl!!!!! I asked for different samples to play with, the acrylic works a treat as do the PU clear coatings, for some reason it wont penetrate the white, looks very wishy washy, thats why I am putting a white underbase on then the clear coating on top

[Greybeard]

no its an acrylic wetlook top coating, lol, dont ask me to explain the chemistry, Im a girl!!!!!

Shame on you

John
EDIT ..but you have just given me a new way of looking at the whole problem of finding suitable surfaces for pressing onto.
I now suspect the usual explanation of how the surface of a pu coating is missing a detail.
I think the process going on is one of adsorption, not absoprtion.

If you take a lump of carbon and drop it into a dye solution, nothing much will happen.
But if you 'activate' the surface of another lump, say by heating it up till it's red hot, then after it's cooled drop that in, it adsorbs the dye molecules onto its surface.
If you then warm it up, the dye will reappear in the solution. this is the adsorption process, and I think it is the process that governs the suitability of some surfaces to work better than others .

In your case, it suggests to me that the filler used to make the primer white (probably titanium dioxide - brilliant white and cheap) may be filling up the 'pores' in the pu surface.
I would suggest that a single coat of pu primer, then a single coat of clear pu would work at least as well, if not better !