The definitive How-To on Table Top Epoxy

table top kit1One of our most popular products is our Cyrstal Clear Table Top Epoxy. This two-part epoxy is not only crystal clear, but UV Resistant and is great for many kinds of projects from River Rock to castings to topping a bar or table. The product has many uses and is relatively easy to use, but there are a few tip and secrets that will give you better results, and an easier experience.

The first step of any resin product is always the surface preparation. You will want to start by sanding the surface down. Once it has been lightly sanded, you do need to make sure it’s completely clean and oil free before applying. Be sure to wipe down the surface with Isopropyl Alcohol before starting. If you are using this product on wood, be sure the wood is completely dry, or it will give off moisture and cloud the coating.

Epoxies are extremely sensitive to temperature and our Table Top is no different. If your environment is under 60 degrees, the epoxy will likely not cure out properly. Also, if the temperature is over 90, you will find an extremely quick working time. One thing our technicians always recommend is setting the product in warm water for a half hour to get the epoxy warm. You will find it flows better and makes getting rid of air bubbles much easier.

Fiberglass Coatings Crystal Clear Table Top Epoxy is a 1:1 ratio mixture. The most important part of this whole process is getting the two parts mixed properly before application.

To start, be sure to have proper protection, like an apron, gloves, a face mask and safety glasses. Once you have the proper protection have two separate mix and measure cups and pour each mixture separately and exactly the same. Do not pour more than you need, as whatever you mix will get hard and won’t be reusable. From there, pour the two mixtures into a third cup, giving you the most accurate mixture. Be sure to pour as close together as you can, as air bubbles are your enemy here.

After scraping the cups and getting the mixture out comes the toughest part; stirring. Many people want to whip it like a custard or pudding. While those things are delicious, it does add air to your mixture, meaning cloudiness and air bubbles you may not be able to get out. So, stir the mixture slowly for a full 3 minutes. Set a timer, if you need to, but do not skimp on the timing. As you stir, you should see the mixture go from cloudy to crystal clear, with hopefully little to no air bubbles.

Once the two components have been thoroughly mixed, it’s time to apply the product. You need to remember you have a fairly small working time, depending on the temperature. At 70 degrees, you have roughly 20 minutes before it starts to really get hard, but at 90 degrees, your working times is a bit less than 10 minutes. When applying, you pour the syrup-like liquid on to your surface and spread the liquid evenly over the surface. I like to just put a glove on my hand and spread it that way, but you can use a brush if you choose.

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Once the product has been leveled, it will continue to self-level to a point, but it will need help. Be sure to allow it to drip down the sides, or if you build a dam, ensure it doesn’t leak.

Now, you want to get the air bubbles out. If you find most of your air bubbles are on the surface, you are in luck. Our Bust-a-Bubble spray is great for drawing them up and out. Simply give a light spray to the product and watch the bubble go away. Do not let the Bust-a-Bubble pool; you are only looking for one or two spritzes to do the trick. Bust-a-Bubble works best with the thicker pours. If your project is a thin film, using too much will slow or stop the curing.

If you have bigger, deeper bubbles, you will need to try something different. The best thing is generally a heat gun. Adding heat to the mixture thins the epoxy, allowing the bubble to float to the surface and pop. Some people will also use a toothpick to pop the bubbles. I’ve found, for deep bubbles, a combination of the two works great.

The thinner the mixture, the longer it will start to get tacky. If the pour is fairly thick, it will get hard in about an hour, with a complete cure coming in about 24 hours. If it’s a thin pour, since there is very little heat given off, you will see a complete cure taking closer to 48 hours.

Multiple pours are absolutely fine with Table Top Epoxy. You want to wait until the product is tacky and setup before applying your next coat. As with before, be sure to apply slowly to not get air bubbles and keep applying until you achieve the thickness you need. If you do let it completely cure, you will need to sand the product down to 220 grit, wash the product with soap and water and re-clean with Isopropyl Alcohol before applying a new coat, so it’s best to apply while still tacky.

Remember that while our Table Top has a better UV protection than the rest, it doesn’t mean it’s meant for something with direct sunlight. We recommend keeping it out of the direct sunlight to avoid yellowing.

Another benefit of using Table Top is how easy it is to repair. If you have scratches or dings on your table, you can always lightly sand the surface and add another layer to give it that new table finish. Just be sure to clean your surface again before applying that new coat.

Table Top can also be tinted or pigmented. We sell many colors you can add to the mix to change the color, from a see-through color, to a dense color. You will find very little pigment goes a long way. Adding too much pigment can slow or stop curing, so a little dab will do ya’.

After your table is done, I recommend adding a UV Polymer wax to your covering to add even more UV protection and also bring out the shine. We sell a Presta brand that works very well!

So, there you go! Everything you needed to know about Table Top. Easy, right? If you have questions, remember, we have technicians that are available to answer any other questions you have, so don’t be afraid to ask!

How-to Guide – Hand Lay-up on Fiberglass Molds

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1. PREPARING THE MOLD

Remove dust and dirt from mold.

a. If mold is of plaster, wood, or new fiberglass, apply soft wax (Wax #2) and buff with soft towel. Then spray or brush with PVA parting compound and allow to dry.

b. If mold material is glass, metal, ceramic, or well-cured fiberglass, apply three coats of hard wax, carnauba type, buffing between each coat.

2. APPLYING THE GELCOAT

a. If gelcoat is to be brushed on, allow the first coat to cure and then apply second coat to make sure there are no light spots.

b. If gelcoat is to be sprayed on with a gelcoat gun, spray up to a thickness of .015” to .020”. When gelcoat has cured long enough that your fingernail cannot easily scrape it free (test at edge of mold where damage will not show on part) then proceed with next step.

3. LAY-UP SKIN COAT

Cut ¾ or 1 oz. mat to cover your part. Brush catalyzed resin over the cured gelcoat and then apply the mat. Work with the roller, adding more resin where necessary until all white areas in the mat fibers have disappeared and all air bubbles have escaped. A mohair roller is ideal for rolling in the resin, and a ribbed plastic or aluminum roller assists greatly in popping any remaining bubbles. Avoid leaving excess resin standing in puddles. Resin-rich areas weaken the part. Where rollers will not reach, brushes must be used. When this step is complete, clean all your tools in acetone. Allow skin coat to cure before next step.

  1. LAYING FIBERGLASS REINFORCEMENT

For a 12 ft. boat, two layers of 1½ oz. or 2 oz. mat and one layer of roving may be adequate, depending upon design. For a 14 ft. boat, an additional layer of mat and roving will add additional strength. Apply each layer as in step 3, but it will not be necessary to wait for curing between these layers. Be sure to shake all acetone out of brushes and rollers before applying resin. Acetone drips can result in uncured spots in the lay-up.

  1. TRIM

On a small lay-up, the fiberglass laminate which hangs over the edge of the mold can be trimmed off easily with a razor knife if you catch the “trim stage,” of the period after the lay-up has gelled but before it has hardened. On a larger lay-up, it can be trimmed with a saw or diamond blade.

  1. CURE

The cure may take from two hours to overnight, depending upon turnover desired, temperature, catalyzation, and nature of the part. If laid up in a female mold, longer cure will affect shrinkage and easier parting. In the case of the male mold, the part comes off more easily before it shrinks appreciably. If the part is subject to warping, a longer cure may be necessary. In any case, when the part is removed, it should be supported in its desired shape until fully cured.

  1. REMOVE PART FROM MOLD

First, examine the trim edge all the way around the mold and make sure there is no resin bridging the line between the mold and the part. Sand this edge where necessary. Then wooden or plastic wedges can be pushed into the edges to start the separation. Continue separation by pulling and flexing. In some cases, it is necessary to drill a small hole in the mold and apply air or water pressure.

  1. FINISH

Trim edges and back of part may need to be sanded and coated with surfacing resin or interior gelcoat.

  1. GELCOAT PROBLEMS

Alligatoring,” or wrinkling of the gelcoat may be due to the following reasons:

  1. Gelcoat is too thin in spots; consequently it does not completely cure.
  2. Insufficient hardener added, or hardener not mixed well enough. In general, it is best to use about twice as much hardener in gelcoat as in lay-up resin at the same room temperature, since the gelcoat goes on thinner than a mat lay-up.
  3. Gelcoat has not cured long enough before mat lay-up.
  4. Acetone from tools drips onto gelcoat or into skin lay-up.

A Glossary of 122 Industry Terms –

In the world of gelcoat and resin, like every industry, there are terms used that are considered common-place. We have an extensive glossary to help with those terms. Have some others you think we should add? Message us and let us know!

A

Accelerator – An additive to polyester resin that reacts with the catalyst to speed up polymerization. This is required in room temperature cured resins. See Promoter.

Acetone – In an FRP context, acetone is primarily useful as a cleaning solvent for removal of uncured resin from applicator equipment and clothing. Very flammable liquid.

Additive – Substance added to resin mix to impart special performance qualities, such as ultraviolet absorbers, flame retarding materials (antimony trioxide, chlorinated waxes).

Air-drying – To cure at room temperature with the addition of catalyst but without the assistance of heat and pressure.

Alligatoring – Wrinkling of the gelcoat film that resembles alligator hide.

B

Bag molding – A technique for forming and pressure-hardening plastics or plastics laminates by means of air pressure, vacuum and/or heat in a flexible or semi-flexible bag or autoclave, usually in connection with a rigid die or mold.

Barcol hardness – A determination of surface hardness of a polyester using a Barcol Impressor.

Benzoyl Peroxide (BPO) – The catalyst used in conjunction with aniline accelerators or where heat is used as an accelerator.

Bi-directional – An arrangement of the reinforcing fiber strands in which half the strands are laid at right angles to the other half, a directional pattern that gives the maximum product strength to those two directions.

Binder – A resin soluble adhesive that secures the random fibers in chopped strand mat or continuous strand roving.

Blister – A flaw or air pocket between layers of laminant or between the gelcoat film and the first layer of laminant.

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Tech Question: “Can I apply resin to foam?”

foam-blockMany of our customers look to make sculptures out of fiberglass and resin. Foam is a common material as it’s easy to carve and sand to your desired shape. But, can you put Polyester resin on the top of it? It’s a question we get asked constantly.

Your first step needs to be finding out what kind of foam it is. Certain types of foam have different temperature variations. Polyurethane foam, like the kinds we sell in 4’ x 8’ sheets offer different temperature variations from things like Polystyrene. Once you figure out which foam you have, you can figure out what you need to do.

With Polyurethane foam, it will easily withstand Polyester or Epoxy resin applied to the top of it without having to do anything special. We recommend scuffing the surface with some sandpaper to get the best bond, but once the standard surface prep is done, you can apply your gelcoat, resin or epoxy.Polyurethane foam

With Polystyrene or Styrofoam, you can’t directly apply Polyester or Epoxy directly to Styrofoam, as it will melt the foam. Fortunately, we have a couple of products you can use to still make it work. The first product is an FGCI product called Styrocoat that uses a standard epoxy activator and will provide a protective shell over the Styrofoam. The other product is made by Duratec and is called Styro-Shield. Styro-Shield is a Polyester-based product that uses MEK-P and will provide a protective coating once hard.

So, no matter what kind of foam you use, we have a way to make your fiberglass mold or fiberglass-based product. Don’t forget that if you have questions, we are here to help! Give us a call at 1-800-272-7890, or e-mail us or contact us through Facebook or Twitter!