Polyester clear?!

[SpitfireIV]

Quick one....

Polyester clear coat or a 'polyester based' clear coat, does this mean anything to you guys or can anyone point me in the direction of where I might find such a product?

I've been searching online but cant seem to find much relating to it but I've heard of it being used in regards to application on wood products (builds heavy and polishes like glass). I've used epoxy pours with fantastic results but would like a 'sprayable' product.

Thanks for any help

 

[richie00boy]

Are you sure they are not referring to "poly" clear? Americans use that term a lot and it's polyurethane clear varnish.

 

[norsa]

Polyester to us is normally refering to the colour coat (base coat) The problem is terminology changes so much which leads to confusion. Can't say I've come across polyester clear.
Nick

 

[Dcal]

I've used this PU in acid-catalyst, the do quite a range.
The one I used was very easy to use and gave good results.

Morrells | Morrells | Acid-Catalyst Lacquers

Morrells acid-catalyst lacquer range offers FIRA Severe Use with easy sanding and quick drying

www.morrells.co.uk

http://www.mig-welding.co.uk/forum/attachments/img_2804-jpg.136603/?temp_hash=b7b011806cc155eef02f55ae696b966a

 

[Ctreanor13]

If fairly sure our clear powder coat at work is polyester based. We also use polyeurothane as well for more extreme environments. I have found the polyester always tints the colour of the brass underneath and gives a different appearance

 

[Keith 66]

Clear Polyester is commonly used as a Gel coat in GRP where a high degree of water proofing durability is needed, typically on boats below the waterline, it also has the quality control advantage of showing air bubbles in the laminate so they can be rolled out.
I dont know if polyester is used as a clear coating for wood, it does not have the adhesive power of epoxy so would be dubious.
2K Polyurethane clear coat is a different matter & can be cut back & polished, It has good UV resistance so should last well.
Epoxies have very poor UV resistance so are a bad choice for anything thats going to get sun on it.
They will go gingery & fail in a year or so.
Makes me wonder what all these fancy river tables are going to look like a few years down the line if put anywhere in the sunlight!

 

[SpitfireIV]

Thanks for the help and advice all.

Dcal, you put me on the right track, Morrells do a polyester lacquer! That's a great lead. I'm in Ireland but I believe they have a premises in Dublin so I'll be in touch tomorrow to find out more.

Keith, it's the high solids I'm after really, the polyesters have in the 90% solids i believe compared to some UHS 2k acrylic I've been using that only has 58% solids. A number of the prestigious dash and interior trim makers use the polyester based stuff as it builds on quick and can be cut back. I was under the impression that the new technology stuff had uv inhibitors etc in it, but I'll be sure to find out.

Cheers!

 

[Keith 66]

Polyester lacquer should be fine, a mate of mine uses it a lot. If its got UV inhibitor you shouldnt have any probs.
Epoxies on the other hand are sometimes said by manufacturers to be UV resistant, last one i used on a boat SP Systems Spa bond failed within 2 years and it had been overcoated with 5 coats of 2pack linear polyurethane varnish. Never again will i use it as the refinish job took 3 times longer than a normal one as the stuff is so hard. Ever since i have been very dubious about epoxies & varnish.

 

[Dcal]

Thanks for the help and advice all.

Dcal, you put me on the right track, Morrells do a polyester lacquer! That's a great lead. I'm in Ireland but I believe they have a premises in Dublin so I'll be in touch tomorrow to find out more.

Keith, it's the high solids I'm after really, the polyesters have in the 90% solids i believe compared to some UHS 2k acrylic I've been using that only has 58% solids. A number of the prestigious dash and interior trim makers use the polyester based stuff as it builds on quick and can be cut back. I was under the impression that the new technology stuff had uv inhibitors etc in it, but I'll be sure to find out.

Cheers!

Hi Keith, interesting results you've had with the epoxy.
On a recent thread, someone was asking if clear lacquer would prevent the chalking of epoxy paint. (Jotun 80)
I didn’t know but thought it might if the clear stopped UV light and it wouldn’t matter if did. Now I'm now wondering if I gave a bum steer.

Most of the paints for high exposure, 25year to first maintenance in marine splash zone, are epoxies (the Forth Bridge is painted with it) so I’m surprised an epoxy repair failed so quickly.
All the manufacturers say the chalking of the epoxy won't affect the performance of the coating and they can normally be used as a one coat system, however if colour fastness is important they should be overcoated with a PU top coat.
I know very little about resins so just interested

Also I always thought Polyesters were more porous than epoxies, well certainly the body fillers, spray fillers and base coats are, but I wonder if I'm missing something.

 

[Keith 66]

I worked as a wooden boatbuilder & restorer plus a lot of Grp repairs but have always kept abreast of modern materials.
Virtually all the wooden boatbuilders i know prefer traditional clear coatings ie oil based, this is largely due to ease of re finishing when its time. Uv levels on the water are high & salt plays merry hell with varnish anyway.
Epoxy failures due to UV degradation are a fact of life with epoxy resins used for marine gluing & laminating & its pretty well accepted that you must paint it to protect it from UV, this is usually with a 2k polyurethane paint in which case it will last for donkeys years.
If you have used a 2k Polyurethane clear coat varnish, Failure of the epoxy shows as going a gingery colour under the & there is no stopping it once its started.
It is true that polyesters are more porous than epoxies, but being less porous does not mean epoxy is UV resistant.

 

[SpitfireIV]

Just an update for anyone that may be interested. So I sourced some supplies from Morrells, a UHS polyester clear basecoat and a 'wet look' PU top coat; just what I was after.

Thanks for all the help and info