Varnish Questions & Answers by Epifanes
What is the best way to remove old finish?
There is no right way or wrong way to strip varnish. Whatever works for you, is the best way. Our recommendations are based on our own experiences and preferences.
First, begin with a good (6 or more. You can't have too many) selection of scrapers. Go nuts, experiment with a variety of styles, brands, and shapes. These should be treated as tools. That is what they are. Learn how to sharpen them. We cannot emphasize enough the value of a sharp scraper. Books should be written on this subject. If you want to know more, ask us.
Next, experiment with stripping methods. There are a vast number of chemicals out there to choose from. We do not use chemicals. We have tried most of them and have always returned to a heat (hot air) gun and sharp scrapers. This method is by far the least messy and most effective for us. However, having said this, try different methods. You may discover a combination that works better for you. That is o.k. On the subject of
heat guns, we have tried them all from the most expensive at $140.00 to a $25.00 Black & Decker. We use the Black & Decker exclusively. Why? It is a fraction of the weight and produces the same thing. Hot air!
Once you have determined the method that works best for you and your boat, get organized. Establish a sharpening area, lay out your tools, clean your space, put on your favorite music and begin. Start at one end and work your way to the other. This sounds basic but avoid the tendency to jump form here to there. You will have better success if you approach the job logically and orderly.
You may find that stripping is a two-stage process. Strip off the bulk of the varnish first time around then, hit it a second time removing the residue and bringing the wood back to fresh. This is o.k. too. Scrapers remove more material easier and faster than sandpaper. Stay with them until the job is done. If you find that your scrapers do not work on a particularly tight spot, make one that does. With an old file and a grinder, one can make an excellent specialized scraper.
Deck seams. The old caulk, and it may be very old, very hard putty, needs to be removed. Do not try to save this. You will not be able to and still retain the integrity between the caulking and the seam edges. Again, a heat gun works best. Make a gouging tool that fits your seam width. Take your time and be careful! Do not lie awake at night devising a "router/circular saw seam removal machine". We have not seen one
that works yet.
Take your time and enjoy yourself! This is fun remember??
What is the best way to care for a good Varnish brush?
Although the tendency to use a foam brush for the ultimate in convenience may be great, there is absolutely nothing as satisfying as a good quality, natural bristle varnish brush. When selecting a brush watch for the following:
A true varnish brush will have slightly shorter bristles in order to "bite" into a heavier product like marine varnish. This makes for a slightly stiffer bristle.
Check the bristle ends. A good brush will have split ends (just like a split hair).
Watch for the way the bristles have been cut or chiseled. This will determine how well the brush will smooth the varnish as well as how well it will draw the air from the finish.
It is difficult to determine how the bristles have been set. Epoxy is normal, vulcanized rubber is great.
Ensure that the ferule (metal part) is well put together. Hopefully, the material used is stainless.
If the brush has passed the test so far, chances are the handle is hardwood. At the very least, the quality of the handle will be a good indicator as to the standard used in constructing the rest of the brush.
New brushes are very dirty! Take some time to break in a new brush. Use it and clean it out several times with mineral spirits. Keep in mind it may take many sessions to really get it clean. We have brushes that are reserved for final coat only. We still spend up to an hour cleaning a brush prior to a final coat. Sit in front of the TV and flick the bristles back and forth. In front of a bright light, you will be amazed at what will come out of it.
The best way to store a good brush is to keep it wet, suspended in diesel fuel or kerosene. Yes, diesel. Nothing works better as far as we are concerned. Diesel is oily enough to keep the bristles nice and soft while still having enough cutting capability to keep the brush clean. We have a brush that is easily sixteen years old. Prior to varnishing, clean the diesel from the brush with mineral spirits, rinsing and spinning several times. Once done repeat the process. Your brush will be as happy as can be in a diesel or kerosene bath. Change the diesel once or twice a year.
Why do varnish manufacturers recommend thinning?
Proper thinning of the varnish is very important. If you apply the first coat of varnish full strength, the entire varnish system will adhere to a coat that is sitting on top of the wood. Not good. Therefore, significant thinning (50% or 1/2 & 1/2) of the first coat is very important. A very thin "sealer" coat will give maximum penetration and good grip for the subsequent system. It is quite normal for a manufacturer to recommend a thinning of the first few coats progressively building to full strength.
Applying varnish over stained wood can cause particular adhesion problems. If filler stain has been used, the aggregate in the stain can block the penetration of even very thin varnish. In some cases, it is advisable to rub in the first coat of thinned varnish as you would stain to ensure that the material penetrates properly.
Once the sealer coats have been applied, varnish should be used full strength. If the varnish is not flowing well or it feels "brushy" possibly due to weather conditions, small amounts (usually 5% or so) of thinner can be added to make it a bit more user friendly.
Check with the manufacturer of whatever varnish you happen to be using. There are great additives available to help you through tougher conditions. Make sure that you follow the manufacturers instructions carefully. Concocting your own blend can lead to greater problems down the road. As an example, adding too much accelerator or "Jap dryer" can create a harder, less flexible finish. This can greatly reduce the overall life of
I am experiencing air bubbles drying in my varnish?
We will bet that what you are experiencing is dust. Dust and/or lint particles that dry in the varnish can form tiny craters that can certainly look like air bubbles. It is very rare for air to dry in a coat of varnish. Let's try to figure out where this dust might be coming from. If the coat looks great upon completion but several hours later looks as if someone has taken a saltshaker to your boat, then the dust problem is most likely airborne. If the dust occurs right away, brushes and the initial cleanliness of the surface are more likely to be the culprits.
Here are a few, sometimes overlooked, sources of dust:
Although your brush may appear clean, try flicking the bristles in front of a bright lamp. You will be amazed at what comes out of it. Turn on the TV and be patient. It can take an hour. Do not assume that a new brush is clean, new brushes are particularly dusty.
Be aware of what is happening overhead, it may be that your basement ceiling is shedding dust each time someone crosses the room upstairs.
Fluorescent lights will act as a dust magnet until the moment you turn them off.
Check your clothing. Wear dampened Tyvek coveralls.
Mask or temporarily seal all screw holes. Your brush will certainly pull out whatever is hiding in those holes. We know a painter that varnishes in the nude listening to Vivaldi. Hey, whatever works.
I recently purchased a 15' pre-war Century Utility that has been out of the water for at least two years. After stripping and sanding the hull, the stain and two sealer coats have been applied. What danger, if any, is there of the varnish cracking once the boat is re-hydrated? How many coats of varnish would you suggest that I apply? Also, is the quality of varnish I use a factor?
It sounds like you are doing everything right so far. Assuming that you are using better quality varnish (more flexibility) there really is no danger of the finish "cracking" once back in the water. However, what will happen if you apply the entire system now is that the varnish will be squeezed from between the planks as they swell forming a hard ridge. There is nothing wrong with this from an integrity point of view, however it is unsightly. Resolve the problem using the following procedure: In order to protect the boat from shop wear, insure that several sealer coats have been applied. Slowly increase the moisture content of the wood back to normal. This can be accomplished by draping the
boat in plastic and running a couple of vaporizers or, lay down a bed of wet sawdust. Here is something else to keep in mind, if the decks are caulked, the seams will become proud if they are laid now rather than after the boat has adjusted to "normal". This can pose a greater problem. Any major change in the expansion or contraction of the decks may result in the seams parting company with the planks causing them to leak. Once the
wood has normalized, continue with the varnish system. Seven to ten coats in total should bring the boat to show quality finish.
As mentioned above, the quality of the varnish certainly plays an important factor in any job. Very basically, varnish is oil, resin, solvent and a few additives that help the product dry, and repel U.V. etc. The lesser quality the varnish, the more solvent (cheapest ingredient) there will likely be. The quality and quantity of oils and resins will determine the weather resistance and longevity of the finish. Generally, better quality oils and resins provide a more flexible finish that has the ability to expand and contract with a piece of wood that is constantly on the move. In conclusion, look for varnishes that contain better quality oils like Tung Oil and a higher solids content.
To what extent if any, does climate play a role in the life expectancy of a boat's finish and/or the life of the boat itself? i.e. the cold northern climate vs. the hot, humid south vs. the dryness of the west. Should boats in different regions have different numbers of varnish coats for additional protection?
Climate certainly plays an important role in the life expectancy of a boat's finish. Let's take a fictitious boat and move it around. We'll say an 18 foot mahogany planked runabout, with painted topsides and varnished decks and interior. First scenario will be in the mixed climate of the northeast or northwest. This can sometimes be the hardest climate to deal with, hot in the summer, cold in the winter and everything else in between. Heat and cold, naturally, causes expansion and contraction. Alone, this is not a terrible thing; a good quality varnish or alkyd enamel finish will have the ability to take up that movement. However, introduce moisture and UV and you have more to contend with.
If the boat sees consistent exposure over the summer months, even if that means a season of 4 months, expect to apply one to two coats of varnish annually. The painted surfaces will last years before requiring a maintenance coat unless, they are showing signs of normal wear and tear like fender scratches etc. Then it simply becomes an appearance issue. If however, that same boat is kept in a covered boathouse or, trailered and kept in a garage when not being used, expect a coat of varnish every 3-5 years! Exposure to the sun makes all of the difference in most cases. Now, during the winter, if the boat is stored outdoors and covered with a tarp, expect to see damage to either the painted or varnished surfaces. Damage as in lifting or pealing at the joints.
This will be caused primarily by moisture, not necessarily the cold. If the same boat is stored in unheated indoor space, there will be little or no deterioration. If we take the same boat and move it south, take the moisture out of the scenario and add mega doses of UV. Once again, if exposed to the sun all summer long; expect 2-4 coats of varnish annually. Covered, maybe 1-2 coats every couple of years. Winter is not as big an issue because it is a moderate extension of the summer. Imagine the varnish is hand cream, every once in a while, depending on the sun and exposure, your surfaces need to be replenished and moisturized. Fresh coats of varnish accomplish the same thing.
Generally, a varnish system should be 7-8 coats. If in the south, or exposed to lots of UV, step that up by two coats. In conclusion, protection from direct exposure to ultra violet and excessive moisture will ensure best success.
Could you explain the differences between varnishes that require sanding between coats and those that don't require sanding? Is there a difference in life expectancy between the two? Also, what is the effective shelf life of varnish? Does storage temperature play a
There are many, many varnishes; clear finishes and hybrid clear coatings on the market today. Most manufacturers have made some attempt in various directions in order to create an easier, faster, longer lasting finish. Unfortunately, we can only comment in any detail on our own products. For obvious reasons, it would be unfair to do otherwise.
Twelve years ago, Epifanes produced a finish very similar to our Clear High Gloss Varnish, called Wood Finish Gloss. It is a tung oil, alkyd resin based finish just like our varnish however, it does contain ingredients not normally found in traditional varnishes producing one significant difference. Wood Finish does not require sanding between coats provided the next coat is applied within a 72-hour period. This feature has an obvious effect on the amount of labor and time required to build a finish from bare wood. Sanding is optional. Wood Finish changes the focus of sanding completely. You are no longer sanding for adhesion but appearance only. Are you sacrificing any integrity by using this product? At this point in time no. However, having said that, we are recommending top coating this product with our varnish for the ultimate in performance. We have 97 years experience with our Clear High Gloss Varnish and only twelve years with the Woodfinish. Time will tell.
Unopened varnish has virtually no shelf life. We have opened five-year-old varnish that has been perfectly good. The oils and resins may change color and consistency slightly but essentially the product should be fine. Once opened however, the life of the varnish will be greatly reduced. Each time it is opened, a portion of the solvent evaporates leaving a thicker mixture more prone to solidifying. Store the container upside down, reduce the air space, and keep the varnish cool. I have more problems keeping varnish in Florida than Maine. The temperature plays a major roll. Store in a cool area of the basement.
I am having trouble getting successive coats of varnish to smooth out on my boat.What level or grit of sandpaper should I use in between each coat and how hard or how much should I sand the previous coat in order for the next coat to lay up smoothly?
The purpose of sanding is to create a mechanical bond, or "tooth", between two layers of finish. In addition, sanding also flattens the surface creating a smoother surface and improving the appearance of the subsequent coat. Please keep in mind that the purpose of varnish or any other coating is to protect a piece of wood. Don't lose sight of this. Over sanding for the sake of appearance may result in a thin finish with little or no protection.
Mil thickness is everything in a varnish system. Let's start at the beginning. Bare wood should normally be prepared to approximately 100 or 120 grit. Anything much finer than this will not create adequate adhesion for that ever so important first coat. Dry paper of about 220 grit should come next to help knock off the raised grain after the first few coats. Once the grain fills and closes, switch to 320 wet or dry. 320 will offer enough adhesion without taking off too much varnish. Stick with 320 right through until the end. If you are using a heavy body varnish, 320 sanding scratches should not show through. Switching to 400 somewhere prior to your final coat is a good idea but, not essential. Anything finer than 400 grit will not offer enough adhesion. Thorough sanding is important.
In answer to your question, if you are looking for a "show quality" finish, it is essential that the finish is "dead