Lacquer, Oil, Solvent, Alcohol, Shellac, Beetles?

[gliders]

I think it would be useful to have a definitive list/explanation of what exactly is what when it comes to the make up of the paints, primers etc.we use. For instance in u.s it seams laquer based means solvent based , but not alcohol based, whereas I would call alcohol a solvent...etc. if you look at various wood/model/craft forum's around the world it definitely causes confusion. Sure it could be useful for clarity.

[mark poulson]

Gliders,

I think all the info about the different top coats and finishes can be found if you google it.

I don't know how this site could assemble a breakdown of all of them without either quoting directly from the manufacturers, or just doing a shallow listing with no real info.

[gliders]

Your probably right mark, could be tricky! Maybe your the man for the job , and while your at it you could sort out the fluorescence/phosphorescent white issues while you're at it! ........cheers.

[BobP]

Water is a solvent too. Most of us think of solvents as being alcohol or petroleum based coatings, and most finish coating problems arise when petroleum based solvents react with one another to wrinkle or bubble a finish. It isn't always clear what exactly a coating contains and it can be hard to find this out. For example, there's a difference between virgin lacquer thinner and the Klean Strip lacquer thinner that many of us buy at a home improvement store. What is it? I think the Klean Strip can contain just about anything the company wants to throw into the batch. And I don't really know what "virgin" thinner contains either.

Just as important is what a builder THINKS defines a particular type of coating and what role he thinks it plays in his coating regimen. What really is a "primer"? What is an undercoating? Are they different from a wood waterproofing coating? Or is epoxy a primer? Does it become a primer if you sand it before applying the paint? Reading TU posts over many years, it's clear that there are about as many answers as there are TU'ers. So I think you are wading in turbulent water. All I can say for sure is there are combinations of finish coatings that through experimentation and general usage among builders seem to work well while others don't.

Edited September 22, 2016 by BobP

[gliders]

Agree completely bob p. I'm glad I got my system sorted, but must be confusing to guy's starting, called the learning process I guess. Regarding wading turbulent waters, your right, Thats why I passed the buck! I'm going wading later but in calm waters only, for pike!

[Musky Glenn]

I am not an authority on chemical composition by any stretch of the imagination. I have worked with a lot of different finishes on furniture and cabinets. I am going to list some things that I am pretty sure are correct.

 

1.  solvent is not a term to be used when describing finishes.

2. You can put enamel paint over lacquer

3. You can not put lacquer over enamel (you may get lucky if the lacquer is applied thin so it can flash off quickly.

4. sanding sealers, varnishes are an oil base finish and can be thinned with paint thinner

5. polyurethane is also oil base but seems to be more moisture resistant than sealers and varnishes.

6. acrylic urethane is referred to as water based and can be cleaned up with water before it dries.

7. lacquer is lacquer based as is finger nail polish

If you are using/planning to use these finishes, apply a good coat to a scrap piece of wood, let dry and place in a bucket of water over night. Notice changes in size, weight and depth it sits in water.

 

Those are all products that I would suspect to give trouble from time to time. Mixing different chemical bases can cause trouble. Lacquer bonds by fusing with the layer under neath. The other finishes mentioned bond by adhering to the layer below. Thus the need to sand between coats.

For me personally I stay away from these products because I have seen problems when trying to stop moisture from entering wood. Usually not a problem with lures, but sunlight kills these clear finishes over time. I know that many of you use some or all of these products with good results. Let me know if you do. If I have misrepresented any thing PLEASE let me know. I am thick skinned and want to be correct in what I have stated. Thank you, Glenn Grindstaff (Musky Glenn)

[gliders]

Hats off for wading in musky glen, hope you got on chest waders!

[mark poulson]

Your probably right mark, could be tricky! Maybe your the man for the job , and while your at it you could sort out the fluorescence/phosphorescent white issues while you're at it! ........cheers.

 

Gliders.

I have to respectfully decline your invitation.  It would be like trying to herd cats.

[hazmail]

I tried shellac as a clear coat many moons ago (hard clear shellac), looked good and was quite clear (for shellac) BUT---------- one year down the track I had a lot of cracking going on.

Pete

[gliders]

Looks like to deep to wade then! Surely it must be possible to have some sort of consensus on the basic make-up of paint, primer, sealer, topcoat etc. I mean what could be simpler than defining 'laquer based' for example? P.s mark, what about the fluorescence/phosphorecence situation ?

[gliders]

Probably right guy's, but must be a nightmare if translating to another language!

[Musky Glenn]

Remember I told you I wasn't an authority on this stuff. I looked up the definition of lacquer and there is that word I said didn't belong in finishes. SOLVENT. What I meant by lacquer being lacquer based was the fact you thin lacquer with lacquer thinner. That is the way I always associated the two.

 

Lacquer is a type of solvent-based product that is made by dissolving nitrocellulose together with plasticizers and pigments in a mixture of volatile solvents. Lacquer also contains a solution of shellac in alcohol that creates a synthetic coating, causing it to form a high gloss surface.

 

If talking about exterior surfaces, there is some debate about the wisdom or switching water based and oil products. Exterior surfaces  are subject to wide ranges of temperature, radiant heat from sunshine and humidity, to which interior surfaces are not. Oil paints are very hard and britlle and become more so with age. Oil also has a very low coefficient of expansion. "Latex" or acrylic paints expand greatly under these elemants. Therein is the debate about the advisability of mixing the two: Should you bind two surfaces together which are expanding at different rates?

It is best to avoid the question and stick with one or the other on exteriors, especially if a house has had oil for decades.

 

A poorly bonded oil finish can be ripped right off the siding by a well bonded acrylic paint which is schrinking as it dries! There are paint strippers on the market that use this phenomenon to break the bond of old exterior finishes - they bond then schrink causeing massive peeling!

 

Primers and sealers provide an extra measure of assurance that the paint you use will adhere to its surface. In effect, primers and sealers are preparatory products that give the surface tooth that the paint can grip.

-- Primers are formulated to adhere to the substrate and create a uniform surface for the finish coat. Primers stick to the surface; finish coats stick to the primer. Primers penetrate unpainted surfaces, smoothing out any porosity. Primers for wood, whether they are latex or oil-base, contain specialized ingredients that topcoats don't necessarily have, or have in lesser amounts. Stain-inhibiting tannin blockers or preservatives that are found in primers, for instance, are designed to soak into raw wood and seal it so the tannins don't bleed through and stain the finish paint. Primers for other surfaces have similarly specialized ingredients. Latex primers are best for unfinished drywall.
On raw interior wood, oil-base primers may be a better choice because of their surface penetration. On the exterior, a latex primer will last longer because it's more flexible, expanding and contracting with changes in temperature instead of cracking. There are a number of different kinds of primers -- oil-base, shellac-base, water-base -- and each has its own specialty. Ask your retailer for a recommendation on which product to use on the surface you're painting.
-- Sealers, closely related to primers, are formulated to make a porous surface non-porous. They are also used to cover knots and mildew to keep them from showing through the finish coats. You'll find oil-base sealers, as well as products with reactive resins and epoxies. Most of these products clean up with strong petroleum solvents.

Edited September 23, 2016 by Musky Glenn

[gliders]

Thanks glen, that's what I think of when using the term lacquer, or lacquer based . Maybe it's not possible to have universal terminology after all, too many different compounds and different names for them, bob p. Was right , I'm wading out!