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  • An Overview
  • Advantages
  • Mixing & Application Techniques
  • Some Useful Information from
    The Rot Doctor
Application Techniques
Laminating Resin

Layup & Laminating™
Epoxy Resin

An Overview
Layup and Laminating™ Epoxy Resin was originally designed for ease of use in resin/fiberglass/composite construction. It is exceptionally durable in wood/fiberglass/epoxy composites. It was formulated to have a relatively low viscosity and special wetting agents to rapidly wet out fiberglass cloth. When used to wet out fiberglass, you will need approximately one ounce of Layup and Laminating Epoxy Resin (by weight) for each ounce (per yard) of fiberglass cloth. For example, one yard of 6 ounce fiberglass cloth will require 6 ounces (by weight) of Layup and Laminating Epoxy Resin to wet out properly. A gallon of L&L Resin will wet out 10 square yards (8 sq. m.) of 6 ounce fiberglass cloth. We have found it to be an ideal follow-up resin for wood repair, either as a brush on or poured/pumped into cavities previously saturated with Clear Penetrating Epoxy Sealer™.
    Characteristics and Advantages
  • A wood derived resin that mixes 50:50 by volume. The mixing ratio is not critical; + or - 10% off volumes will not alter the cured properties significantly. When first mixed it is thick and "milky," but thins in the pot and turns almost transparent when it is cured. Have resin at room temperature before mixing. At temperatures of 75°F (24°C) and below, we recommend that you give the resin about 15 minutes of "pot cure" time to thin-out before applying. At higher temperatures, use immediately.

  • At temperatures above 80°F (27°C) the set time for the resin will be significantly accelerated. For normal bonding/filling this is not a big issue. You simply mix less resin at one time. When using as a pour-fill into deteriorated wood, however, we recommend that application be delayed until temperatures are below 80°F (27°C), or that the resin be cooled in the can (immerse closed cans in cold water or refrigerate) prior to mixing/applying.

  • Coverage is approximately 45 sq. ft. per gallon at 1/32" (4.1 sq m. per 3.8 liters at 0.8 mm.) when used to laminate wood to wood, wood to fiberglass, or similar applications.

  • The low viscosity was achieved by chemical engineering. There are no plasticizer oils, extender oils, or non-reactant diluent oils that are commonly found in low viscosity systems and which can bleed or migrate with age to cause cracking and loss of adhesion.

  • The cured resin is not brittle. It is slightly flexible so that it can move with the natural flexure or elongation of wood or fiberglass. The relatively long cure time allows resin to penetrate to all vacant wood cavities.

  • Adhesion is superior to petro-based epoxy products.

  • Develops the least "blush" of any commercially available epoxy system.

  • Four-hour thin-film time at 75° F (24° C) allows solvent clean-up; no grinding of cured drips.

  • Full cure guaranteed to 28° F (-2° C). Shelf life in excess of 5 years. Component A is moisture sensitive and must be kept sealed. Do not allow to freeze.

Layup and Laminating Epoxy Resin can also be used as a general purpose adhesive. Normal coverage when using as an adhesive is approximately 45 sq. ft. per gallon at 1/32" (4.1 sq. m. per 3.8 liters at 0.8 mm.). This is the minimum recommended amount to get a strong glue joint. Any less, and there is a risk of not having enough glue in the joint, commonly referred to as "starving the joint". When bonding rough surfaces it is often necessary to use twice as much glue or more to avoid starving the joint. In these cases, coverage will be reduced by half or more. When clamping glue joints, be careful not to over-tighten the clamps.

Mixing & Application Techniques
For best mixing we recommend that Part A and Part B be throughly mixed in one container, and then put into a second container and mixed again with a new mixing stick or a clean paddle blade. This will ensure that no unmixed residue contaminates the final application mix.

While we primarily use L & L Resin to repair rotted wood, it is an excellent fiberglassing resin as well. L & L Resin will wet out fiberglass cloth at the rate of one ounce of resin (by weight) for every ounce (per yard) of fiberglass cloth. For example, one yard of one ounce fiberglass cloth would take one ounce (by weight) of epoxy resin to wet out properly. By volume, this equals approximately two ounces of L & L Resin per ounce (by weight) of fiberglass cloth. A gallon of L & L Resin will wet out 10 square yards (8 sq. m.) of 6 ounce fiberglass cloth.

NOTE: Bulk mixing (more than two quarts at one time) is not advised. It makes a thorough mix more difficult, and it concentrates more resin in one location which will generate induction heat and further accelerate the set time.

Mixed viscosity is 1000 centipoise at 72° F (22° C), comparable to other low viscosity epoxy systems. At 72° F (22° C) the pot life is 1 hour, the thin-film set time is 4 hours, and the time to fully cure will be about 1-2 days. At 55° F (13° C) full cure will be about 2-4 days.

NOTE: For application into tight areas, we prefer to use our Re-useable Poly Caulking Tubes. You fill the tube with L & L Resin, with or without a thickener, put the plunger in and load into a standard caulk gun. After cutting the tip to the size required, squeeze the L & L Resin into place. These empty 10 oz caulking tubes are for sale on our order form as part number 117. Customers have also reported good results with hand-crank transmission oil pumps purchased from your local automotive supplier. Designed to pump thick fluids, and cheap enough to be considered disposable, we feel that they would work fine.

Layup & Laminating Epoxy Resin is often used as a filler or a pourable slurry for voids in wood, fiberglass or concrete. Sawdust, milled/chopped fiberglass and fumed silica (Cab-O-Sil®) are all good general purpose products which can all be added to the resin as thickeners. The more you add the thicker the mix. When adding thickener, it's important that the Layup & Laminating Epoxy Resin be thoroughly mixed BEFORE the thickener is added. The thickener is then added slowly while stirring the mixed resin until the desired consistency is reached.


Be sure to thoroughly scrape sides of mixing container to get all unblended resin.
If in doubt, transfer first mix into a second container and mix again.

Some useful information from The Rot Doctor . . .
Wood is a flexible material composed of long fibers consisting mainly of cellulose (a kind of very high molecular weight sugar) with lots of chemical groups called hydroxyl groups. These readily bond weakly (hydrogen bonds) with water. The wood will swell and shrink depending on the amount of water that has bonded with the cellulose. To get a good bond with paint, epoxy, urethanes or any other coating, you need to reduce the amount of water (and saps and oils) and form a bonding surface for the coating. This is exactly what Clear Penetrating Epoxy Sealer™ does and why it is the single most important first step for preparing wood for any kind of coating or filling. You will never get a truly good rotten wood cure without the CPES™.

That said, let's now look at epoxy resins. Each manufacturer/distributor/formulator discusses their particular resins, activator ratios, thickness or thinness, blushing effects, etc.-- and how much resin you're getting for your dollar. All very interesting. But what about the virgin resin itself? Where does that come from? And does it make a difference?

Approximately 75% of all virgin epoxy resin sold in the U.S. comes from three manufacturers: Shell, Dow and Ciba-Geigy. Only Ciba-Geigy is not back-integrated. These resins are almost always petroleum-based resins (oil, natural gas) and are in turn sold to manufacturer-distributors, such as WEST. They can be "doctored" to some extent, bottled/drummed and sold with activators of various intensities. Price is critical because most epoxy resin in the marine market goes to manufacturers, shops and yards--and we know all about that.

Pic above: Here's a 1/16" (1.6 mm) thick puddle of Layup & Laminating Epoxy Resin™ after a 2 week cure at 72° F (22° C). Just as flexible as the wood it came from, and a lot tougher! It's pure resin-- no additives.
Virgin epoxy resin can also be obtained from wood. It's more expensive to obtain, but yields a tougher and more flexible cured product than petroleum-based products. You'll notice this as soon as you begin to mix it. TRY THIS TEST: Take whatever epoxy resin you're using, mix it with activator as per directions, and pour a small pool on a piece of visquine or kitchen plastic wrap. Let it fully cure. Now pick it up and break it. It snaps apart, right? Some even shatter with flying shards (wear safety glasses!). Make the same test with any of our epoxies and you'll see a dramatic difference--tougher and more flexible. Now we ask you: Which do you want in and on your wood?

All the epoxy products that THE ROT DOCTOR sells are manufactured from wood derived resins. We do this because we know that from start to finish you'll get a better, tougher more flexible bond when repairing wood in your boat or house. Remember, wood is flexible and anything you add to it or on it should be flexible as well. More expensive, sure, but most good things are. You might as well buy the best.

Layup and Laminating Epoxy Resin is a hazardous product. Check the shipping options on the order form for details on shipping hazardous items. For additional information, refer to the Layup and Laminating Epoxy Resin Safety Data Sheet.

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