I am interested to know you guys opinion on how you decide what finish to use and when. I guess I am asking, poly vs lacquer vs varnish vs shellac. I always struggle on which one to use. I know it depends on what you are making but any insight as to what to use and when will be helpful. Right now I pretty much poly everything. Thanks!
I feel your pain on deciding what finish is "the best to use for each project". Poly does cover a huge range of applications and is a great choice in most indoor projects. Where do I start with the rest...... ? lol
All I can really offer is some basic process of determining what finish is appropriate to a project. It takes years to build a thorough knowledge of the myriad types of finishing products available today but you have started this learning process in the right way by asking for some guidance from more experienced woodworkers. I hope this will be some form of constructive help for you.
A lot of the choices in products woodworkers choose to use as a finish is very subjective in that they have a very specific look and feel to every project they make. They rely upon a select few finishes they like even if it is not the best choice or the most popular choice for most woodworkers. Too each their own I always say.
First thing I do is decide on what type of wood I am going to use and it's characteristics. If a hardwood is going to be used for an outdoor project, how does it stand up to the elements on it's own. White Oak for example is extremely durable and can take a lot of abuse and all we have to do with it is to seal it up from the elements and it will last for years with minimal maintenance. A good choice as a sealer for this would be a Spar Urethane or an oil such as Linseed oil for an outdoor or indoor project.
There are other choices such as an all in one product that contains both the stain and a top coat such as Urethane. Just make sure the top coat is an exterior rated product if applicable. This helps to narrow my choices of finish and helps me to determine what approach I am going to take. IE, if it's an outdoor project, will it see a lot of use/abuse and how tough does the finish have to be ? If a project is stained for example, does it require a separate top coat product or is it an all in one product or even just an oil finish such as boiled linseed oil. I generally use an oil based stain for the majority of my projects because of the penetration and richness of the colors. This calls for an oil based top coat or at least a top coat that compatible with an oil stain.
There are some amazingly great water based products on the market now. This is where most producers are headed these days and oil based products are going to be minimized in use over the next few years. Your choices with these products is endless. It just requires you to make a decision on what is best for your project and sometimes you will just have to experiment with these on different kinds of wood material. What I have done over the years was to take scrap pieces of different species of wood and apply a single type of stain to all them. This gives people some form of reference to choose a particular stain for their item. I write the type of stain and top coat on each board as it applies and I keep them stored for future reference. This helps me out as well.
Your use of Poly on all of your projects so far is something you should change but only if it is going to allow you to try something different. The only way you are going to expand your knowledge of suitable finishes is by researching and using products that are identified as good choices. A great resource of projects and appropriate finishes is the YouTube network of woodworkers and many great projects found right here on this site. To expand your knowledge base, try to pick a project that you want to build and use some of the same finishes that they used and glean every scrap of information you can from the process. Try something different every chance you get. This will let you discover new finishes and their uses.
One last point.
Just as important as choosing a finish is the application method of the finish. Try different methods of applying the same finish be it by brush, sponge applicator, rag or spraying. You will glean a great deal of knowledge and skill by doing this. You mentioned Varnish in your post. Varnish can be applied several ways. By brush, rags or cloth and spraying. Varnish can be used as a finish for a wide variety of projects and allow you to achieve an excellent result on bowls, picture frames, tables and chairs and other pieces of furniture. It's just a choice in a finish and one that you should try on many of your projects. Are there other choices ? Absolutely and I covered a few earlier. Applying Varnish is a bit of an art form on large furniture but it is easy to learn and you will only get better at it through using it. Many Lite, thin coats is the secret as is the secret to most finishing.
I hope this helps a bit. Just try different types of finish and always read the info on the product labels as they state the best uses for the product and the application methods. Colin has a ton of easy to build projects and he uses a great variety of finishes to complete them. Use the massive resources of Colin's website and YouTube and over time finishing will become easier and easier.
Thank you so much for being so thorough. The project in question is a oak and walnut lazy susan for the center of a dining table. I am thinking of lacquer instead of poly. Which brings me to another question,(sorry). Is there anything in particular to stay away from if food might come in contact with it? I am not staining it at all just putting a top coat on it. Thanks in advance!!