Teardrops n Tiny Travel Trailers

Perhaps I'm alone in this world, but I don't like varnish. It takes too long to harden and it's too yellow. And I don't like finishing -- I want to be done in a day. So for the three other people out there who hate varnish, what do you use?

I would love to get a discussion going about the plusses/minuses of other clear finishes. How about it?

BTW - stood the walls up on my tear the other day. New pics in the gallery. It sure took a long time to get this far.

Sherman

I sanded off the varnish on mine and put Minwax Clear Shield on. It seems to be doing better........

I also put epoxy on and wish I had done that in the first place.

Sherman, check out my thread Plywood Exterior Finish Extended Durability Testing .

Schaney,
Yeah, I saw your post and even contacted Target Coatings. They recommended their EM9300 and I was intrigued enough I bought a couple gallons to try. I'll keep you posted on how it turns out. In my view spit is better than varnish (nobody has to agree with me) , and this stuff has got to be better than spit because it costs a lot more.

The other thing I liked about target is their bulletin board. They have some posts from several respected woodworkers who like their product. Call it good marketing, but they got me.

I'm still interested in hearing about other products. I know there are several people devoted to clearcoat. I decided, after lots of flip-flopping, that it was a bit too unforgiving for me.

Yes there are some good products in the EMTECH series. The reason I don't use them was you needed to spray them (if I remember correctly) to get the best results. I also wanted the traditional amber varnish tint that the HybriVar has.

Here is my dissertation on the different types of varnishes on the market. This will encompass most solvent based air dry varnishes.

Most varnishes on the market consist of an alkyd resin or polyurethane base, solvents, uv additives, pigments and driers. The resin base is the most important component of the varnish. It is important when selecting a varnish to read the label to determine what type of resin base is used.

Both alkyds and polyurethanes consist of an oil that is reacted with other materials to impart different properties on the resin. Oils commonly used are Soybean, Linseed, Tung, and Tall Oil Fatty Acid (comes from pine trees).

The amount of oil in the resin determines both durability and dry time:
Long Oil - greater than 55% oil - longest durability and slowest dry.

Medium Oil - 40-55% oil - not as durable as the long oils, but faster dry.

Short Oil - less than 40% oil, the least durable, fastest drying.

Polyurethanes consist of a long, medium, or short oil alkyd reacted with an isocyanate to impart better hardness of the coating.

Air dry polyurethanes are not as durable as the two component type.

You can also modify an alkyd with vinyl toluene or styrene (least durable, fastest dry). An acrylic (better durability and hardness) or an epoxy ester (fair exterior durability, better adhesion).

Spar varnishes are alkyd resin modified with a phenolic, rosin or both, and add extra oil in the formulation. These give the resin really good durability, but slow dry.

So the slower the dry, the better exterior durability.

Because all alkyds or polyurethane contain oils, they will all have a certain degree of yellowing. Those that contain tung oil, phenolic resins or rosins will be the darkest.

Water reducible versions can be made from all of the above, however they are hard to find in stores because they have limited shelf life in the can.

For more information you can go to my company's website http://www.ranbar.com and click on the "resins" link and read the headings of the different types of resins out there.

My company supplies resins to paint and coatings manufacturers who then make paints and varnishes. We are strictly a business to business company and do not supply to the consumer. So I am not trying to sell you anything, just provide information.

If you have anymore questions please feel free to ask.

Well, I'm almost speechless. That was a lot to take in at once.

So where in all of that does water reducible polycarbonate urethane fit?

That's what I got, right or wrong. The mfr says I can recoat every two hours, which means I can pretty much walk circles around the trailer with my gun all day and have about 5 coats at the end. That, to me, is finishing!! Gettin' it done!

The varnish I chose for the interior needs about two days between coats. It taxes my patience and I may switch to lacquer if I can convince myself it will hold up.

Wow, thanks for the info Dmckruit.

Because of their shorter dry times is it safe to assume all water reducible clear finishes use short-med oils? I'm curious are there manufactures of long oil water reducible clear finishes?

^ You are correct. Most water reducible resins are short or medium oil because they are commonly used in industrial finishes. There are some long oil water reducibles out there, but they are hard to come by as most industrial coaters want a faster dry to get coated parts off the drying rack faster.

Also, water reducible alkyds are not commonly used in architectural wood coatings because they dry a lot slower than latexes (and also, why would you want to put water on wood). and warping can result.

Another drawback to water reducibles is that they have a short shelf life in the can, so it is difficult for stores to carry them without the stock going bad, so this is mainly why they are sold to industrial customers who can use them quickly.

To make a water reducible varnish, the resin is neutralized with ammonia or an amine and co-solvents, driers, and water is added. If the pH of the varnish drops below 8 the coating seperates into water, and the sticky resin that falls out to the bottom. If the pH stays above 9 then the hydrolization process begins which means the resin begins to degrade into its original components.

Latexes on the other hand, have no resin in them, but acrylic/styrenated monomers. these dry faster and you rarely have pH issues.

The EM9300 is a hybrid resin or a PUD (polyurethane dispersion). This is where you encapsulate the alkyd or polyurethane into an acrylic latex or another resin. In this case, the polyurethane is encapsulated in polycarbonate (or lexan) which is a hard plastic that is dissolved and emulsified into the resin. So in this case you are adding the added benefits of a hard plastic to the properties of the resin.

Sorry for the second spiel.

Thanks, dmckruit.

I think I am learning that the ultimate finish doesn't exist. So it sounds like the EM9300 is (probably) a medium oil modified varnish with some really hard plastic thrown in, and I better get around to using it fairly quickly. Now I'm wishing I hadn't ordered so soon, as I'm a couple months away from finishing.

And don't apologize for going on. Please go on some more. This is what I need.

Sherman

DM,

Thank you for taking the time to put together the information in your post.

It is very helpful to have posts that contain accurate information from people that have experience in a particular field, as opposed to the usual "I think" answers.

Nothing to be sorry about...If someone finds your posts about clear finishes boring, they shouldn't be reading posts about clear finishes.

Rob

48Rob wrote:DM,

Thank you for taking the time to put together the information in your post.

It is very helpful to have posts that contain accurate information from people that have experience in a particular field, as opposed to the usual "I think" answers.

Nothing to be sorry about...If someone finds your posts about clear finishes boring, they shouldn't be reading posts about clear finishes.

Rob

+1 wonderful information!

Great info on clear exterior finishes. Thanks for taking the time to share it with us. However, I'll stick to plain old varnish, because it's cheaper, seems to hold up to my kind of neglect and when applied almost yearly, makes me think that I have a brand new teardrop again. "Wow, don't you have to refinish that wood often?" "Yep, once a year, Here's Your Sign."
Roly

Sherman,

Your stock of the EM9300 should be okay until you are ready to use it. If happens to fall out of solution, you can fix it by adding ammonia to it (get the stuff without colorants and scents) and mix a little in at a time until it all stays in solution.

When using clears, you are pretty much at the mercy of the elements and therefore have a limited life on the coating. Paint works so much better because of the extra pigments, and binders help protect the resin from degradation by the sun. We used to make a silicone paint in white, and my boss took some home and painted his garage 20 years ago, and it still looks as good as the day he put it on.

Also, another comment on yellowing. Varnishes and paints will yellow faster and to a higher degree in the dark than in direct sunlight.

On my build, I am going to coat with "Hillbilly Chrome" (aluminum paint) then cover with aluminum sheet.

Grrr ... winter storm took out net access for 6 day and power for three ...

Dmckruit, Nothing to be sorry about, thisis great info, Thanks.

With HybriVar, Target Coatings told me there are special dries added and it should have a couple of year shelf life. What are dries?

Here are what is listed as it's main ingredients, what can you tell me about it?
Hybrid Alkyd Resin Dispersion
Propylene Glycol Monomethyl Ether
N-Methyl Pyrrolidone
Water

Thanks again