Thread: What is Urethane?

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Sorry all, but following on from my original question about what is latex paint, I remembered that this was another thing that I wasn't sure what the equivalent is over here in the UK.

I've done lots of reading and think (unless I'm getting confused with everything else I've been reading about?) I've found something similar.

I've found the following items at a local DIY store;

http://www.diy.com/diy/jsp/bq/nav.js...&isSearch=true

http://www.diy.com/diy/jsp/bq/nav.js...&isSearch=true

http://www.diy.com/diy/jsp/bq/nav.js...&isSearch=true

http://www.diy.com/diy/jsp/bq/nav.js...&isSearch=true


I saw them yesterday in store (while carting along 6 x 32mm x 10' long plastic plumbing pipes which were flopping all over the place and almost decapitating people!). I think on the back of the cans they all said they can be used for timber as well as concrete, brick, mortar etc.

Do you think this is the same thing as "Spar Urethane"?

Thanks in advance for any replies.

Those are more on the line of your standard sealants like you would use on an outdoor deck or fence. Spar Urethane is more like poly urethane that you put on hardwood floor but is intended for exterior use. It creates like a hard plastic coating on whatever you aplly it to.

Is this similar to spar?


http://www.diy.com/diy/jsp/bq/nav.js...LAID=266948427

http://cgi.ebay.co.uk/Rustins-Polyur...852855ff05ec83

Yes, that's it.

Here's another answer about the difference between poly & spar for those that are wondering.

Spar Urethane is intended for outdoor use and contains a higher amount of solids. It tends to be a softer, more flexible finish. This is primarily because of the temperature changes and harsh conditions outdoor pieces will experience. The finish needs to be flexible in order to survive. Spar urethane may also contain UV inhibitors which help to preserve the color of the wood and avoid graying.

It's oil based so be careful what you get it on, you'll need mineral spirits to remove it. Poly is water based.

http://thewoodwhisperer.com/differen...gular-varnish/

Urethane - a clear plastic based oil ( & poly water based )(comes in hand rubbed-flat look-,semi gloss & hi gloss ).
Spar -oil base- urethane used a lot for clearing marine wood on boats. So look to Marine shops near you if your local hardware store falls short.

Red food coloring in hi gloss urethane= great for permanent dripping blood effects on props ! It dries glossy & has a nice transparent look.Just use oil or water based pending prop.

Thanks guys for your replies.

That's helped a lot, but following a recent visit to a DIY store yesterday, I'm still no further forward. I spoke to an older staff member there that did seem to know what he was talking about, but he had no idea what Urethane was.

I did see a spary can (Plasticote?) of polyurethane, but it was the equivalent of about $12 and probably wouldn't go far. There must be another option & hopefully something I can use in a spray gun.

I'll keep looking - I never give up!

Originally Posted by Phil-the-fear

Thanks guys for your replies.

That's helped a lot, but following a recent visit to a DIY store yesterday, I'm still no further forward. I spoke to an older staff member there that did seem to know what he was talking about, but he had no idea what Urethane was.

I did see a spary can (Plasticote?) of polyurethane, but it was the equivalent of about $12 and probably wouldn't go far. There must be another option & hopefully something I can use in a spray gun.

I'll keep looking - I never give up!

What project are you using it on? Spray on urethane and varnish never looks as good as brush-on and you are correct it costs about 5x as much.

Originally Posted by walkingcorpse

What project are you using it on? Spray on urethane and varnish never looks as good as brush-on and you are correct it costs about 5x as much.

At the moment for papier mache pumpkins, but for general waterproofing of props going outside.

I'm sure I read somewhere that some types of urethane can be applied via a spraygun? I know some of the items I found over here (see my OP - which are not apparently the same as the urethane you have in the states) can be applied via spraygun - about $30 for 5 litres.

Maybe it's a case of trial & error?

Been a long time since I was over in England visiting my cousins, so not sure were you would find anything like this there, but auto supply stores have lacquer based clear gloss sprays- is in the oil based family, not water based-
Also try hardware stores,look for cement / driveway sealer- it's clear & comes in "natural" stone -flat- & gloss.It's water based & is very durable. I've used it to clear props that cannot be urethaned, & I use it to clear surf boards after I've airbrushed graphics on them, & they hold up great !! & darn near anything can be run thru a spray gun as long as it is properly thinned & strained.

Originally Posted by Dark lord

Been a long time since I was over in England visiting my cousins, so not sure were you would find anything like this there, but auto supply stores have lacquer based clear gloss sprays- is in the oil based family, not water based-
Also try hardware stores,look for cement / driveway sealer- it's clear & comes in "natural" stone -flat- & gloss.It's water based & is very durable. I've used it to clear props that cannot be urethaned, & I use it to clear surf boards after I've airbrushed graphics on them, & they hold up great !! & darn near anything can be run thru a spray gun as long as it is properly thinned & strained.

Ok, getting a little confused now!

Let me see if I've got this right;

Urethane = oil based type sealant.
Polyurethane = water based type sealant.

Is that correct?


As mentioned in my original post, I did find some things in my local DIY store and looking at them again, these may be the same as the water based sealants you have over there (polyurethane?), although both can be painted over by using solvent based paint, so this suggests they both fall within the urethane "family" as they must be oil based?

Their properties & uses are detailed here;

Concrete Seal - http://www.thompsonsweatherproofing....oduct.jsp?id=8

One Coat Concrete Seal - http://www.thompsonsweatherproofing....oduct.jsp?id=9


There is also the Cementone Water Seal I found (see my OP) and it's properties & uses are detailed here;

http://www.cementone-india.com/3%20c...0waterseal.htm

Brushes should be cleaned using white spirit (turps), which suggests it is also oil based (so is this urethane also?), but it can be painted over by both oil based paints & emulsion (latex) paints?

All very confusing - does this make any sense to you?

From what you have said I'm assuming that you use the water based sealant on things such as plastic, foam & polystyrene (otherwise the oil based stuff would likely eat into it?).

But what you use for sealing cement/driveways is water based, whereas the items I've given links to above (which we use to do the same thing) appears to be oil based?

I think I need a lie down.......................................