Steady Improvements

Solvent based caulks came under scrutiny by the EPA because they contain mineral spirits/solvents that contribute to air pollution as they dry and/or cure. The solvents that allow them to flow from the caulk tube evaporate into the air and create smog.

For years, the water based caulks have made steady improvements. The first generation ones were somewhat hard and had poor adhesion qualities. The water based caulks of today are awesome. They have better flexibility, better adhesion properties, and they adhere much better to smooth surfaces.

A water based caulk that has been around for nearly 40 years hidden back in the shadows is urethane caulk. Urethane caulks are exciting because they are similar in many respects to the popular silicone caulks. But, in my opinion, urethanes are better.

Urethane caulks will give you these benefits:

 

• Paintable
• High Tear Resistance
• Low Shrinkage
• Water Resistant

Urethane caulks adhere very well to vinyl siding, cedar wood, aluminum siding or gutters, and brick. The only thing they don't stick well to are the polycarbonate plastics. This plastic is the type used for those old fashioned bubble type skylights. Surely you don't have one of those, do you?

One of the reasons urethane caulks stick so well is that they actually bond to things by crosslinking on a molecular level. If you get some on your skin and don't wash it off quickly, it will be there for a few days until the oils from your skin finally loosen it.

Patience is Required

You will note that I said that urethane caulks are paintable. It is true, but you must allow them to cure before you paint them. The curing process can take up to 7 days. This is why you don't see many professional painters use them. They want to caulk and then be able to paint in a few hours. This is a shame since the urethane caulks perform much better than the acrylic caulks.

Ultraviolet (UV) Light Problems

Sunlight can degrade urethane caulks that are not painted. The caulks begin to chalk like old fashioned paints. They still bond well - they just don't end up looking so good. The urethane caulk that offers the best UV resistance is one that is made for marine use. OSI Sealants makes a marine urethane caulk.

You can stop UV degradation by just painting the caulk after it is cured. This is where patience pays off.

Warranties

Have you seen the caulks with the 20, 25, 30 and 50 year warranties? How can they make these claims? Well, most of it is marketing. I guess some of the manufacturers feel you will not keep the tubes, receipts, or even have a clue as to what you used when and if the caulk fails. I can tell you that the longer the warranty on the tube, they better the caulk is inside.

Preserving Caulk

How much caulk have you wasted trying to stick a nail in the end of the tip? I have sure wasted my share.

A top caulk chemist shared a secret with me that I have yet to verify. He said that if you wrap the end of an open caulk tube with Saran Wrap brand sheet plastic - a double layer mind you - and then tape it tightly, the caulk should not dry out for a long period of time.

Caulks can and do dry out in the tube. They have shelf lives of perhaps 12 to 18 months. Some manufacturers are beginning to put expiration dates on the tubes. Look for these when you buy caulk.

Related Articles: Urethane Caulk Companies, Cracks Need Urethane Caulk

Urethane Caulk Companies

The caulk displays I visited just had lots of silicone and acrylic caulks for sale. I even asked an experienced sales clerk at one home center if they had any urethane caulk. He said, "No way. You can only get that at automotive shops that install windshields." Well, while he was still talking I saw a case of urethane caulk. I said, "Look here, you DO have urethane caulk." The clerk was quite embarrassed.

If you call the folks at OSI Sealants, Inc. in Mentor, Ohio, they should be able to tell you who stocks their products. I am hoping someone close to you has it. If not, tell them you would like to buy it off of their website! Call 800-999-8920. You might find other brands of urethane caulks at large brickyards and commercial supply houses. Look in your Yellow Pages under Brick or Brick Supplies. Urethane caulks are used to seal joints in brickwork.

Here are the five types or brands of urethane caulk that OSI makes and the colors available:

• PL Polyurethane Concrete and Masonry Sealant - Gray
• PL Polyurethane Door, Window & Siding Sealant - White, Terratone, Cedar, Limestone, Sandtone
• PL Polyurethane Roof and Flashing Sealant - Black
• PL Polyurethane Concrete Crack Sealant - Limestone Gray
• PL Polyurethane Marine Adhesive Sealant - Ultra White

The other companies that make urethane caulk are:

• 3M Company - 800-234-8068
• Tremco - 800-321-7906 -- Their brand name urethane caulk is Velcum.
• DAP - 800-543-3840 -- You may have a hard time finding their urethane caulk in regular stores!
• Bostik - 414-774-2250 -- Several urethane caulks under Chem-Calk.
• Macklanburg - Duncan - 800-654-8454 -- Their brand name urethane caulk is Sika.
  

Professional Caulk Guns

There is a huge difference between the caulk gun I'll bet you have and a high quality one. Here is how you can tell if you have a low quality gun: #1 Price - if it cost less than $4.00 it is probably a loser. #2 If you pull back the plunger rod and squeeze the handle less than 15 times before the rod slides all the way into the gun, you have an also ran.

Professional guns have much greater force when you squeeze the handle, like 3M's Professional Caulking Gun. It takes 45 or more full handle squeezes to get the rod to fully push into the gun. This extra squeezing gives you much greater flow control when you caulk. OSI sells a pro gun that retails for $13. It is product number 92012. Call 800-624-7767 and ask for customer service. Hyde Tools also sells a similar caulk gun. Many quality paint stores sell Hyde Tool scrapers, putty knives, etc.

Related Articles: Urethane Caulk Benefits, Cracks Need Urethane Caulk

Tape Revolution

Masking tape is a very interesting industry. For nearly 50 years, it just sort of grew without many major improvements or changes to the product. Rubber-based adhesives were applied to a paper strip and you have tape. The trouble is, the tape didn't play well with all of the different surfaces out there. As typically happens, the light bulb went off in someone's head and a new family of tapes was born.

Acrylic Adhesives

Did you know that standard wall paint is simply colored glue? It is a liquid that dries and sticks to surfaces. That is not much different than most other glues. The primary adhesive or glue in paints is an acrylic resin. Acrylic resins are durable and they also are flexible. These are qualities you might find desirable if you were a tape manufacturer.

The trick is to modify the chemistry of the acrylic adhesives to do a wide range of tasks. In fact, that is the message that you need to know. There is no one masking tape that is perfect for all jobs. You need an assortment of tapes to be prepared for all possible challenges.

The tape company chemists simply blend and modify the acrylic adhesives to develop tapes that exhibit different characteristics.

The Players

I am quite certain that there are different masking tape manufacturers out there. But I was only able to find two that are really players in the residential marketplace.

The first and foremost company happens to be the leader in tapes of all sorts. It is the 3M Company.

If my notes are accurate, a scientist at 3M actually invented masking tape back in the 1920's.

3M, as you might expect, has a full line of specialty masking tapes. Not only do they have a tape for every possible job, but the products come in all sorts of different sizes. If you saw their full line of products, you would be impressed to say the least.

The other major player happens to be a company called Henkel Consumer Adhesives. You might more readily recognize them by their logo of the yellow duck with the painters hat. Duck tape, get it?

Read the Labels

Some of the tapes you see may look identical but they indeed are not. Most have very specific purposes, and I highly recommend that you read the labels carefully before you buy. Be sure the tape fits your need and make certain that you can remove it from the work surface in the specified amount of time.

If you are in doubt about tape dwell time or temperature conditions, always call the tape manufacturer's technical help line. Look inside the roll of tape. You will often find this information with you all the time. That was a smart use of space - the inside of the tape roll!

The list that follows was compiled several years ago, when this column was first written. We now think that the Federal Trade Commission believes that these "mildew-proof" claims are not realistic. You may not be able to find these mildew-proof products.

Mildew-Proof Caulk Manufacturers

The next time you get ready to purchase caulk for your bathroom or kitchen, look closely at the labeling. I am quite certain you will see the word mildew. Look again. My guess is that you will frequently see the word "resistant" just after the word "mildew". Mildew-resistant does NOT mean mildew-proof - plain and simple.

Virtually every caulk manufacturer incorporates a certain amount of mildewcides in their caulk products. These mildewcides are a costly item and if you want to make more profit, it makes sense to use as little as possible in the caulk. The big problem is that many, if not all of the mildewcides that are used are water soluble. This means that they can be dissolved and removed from the caulk by water. It just so happens that caulk is used to stop water infiltration, so contact with water is often a daily occurrence.

To make a mildew-proof caulk, a manufacturer needs to purchase the best mildewcides and use a significant amount in each tube of caulk. The strategy is to use more mildewcide in the caulk than can be dissolved by water over the projected life span of the caulk seam. Just about every manufacturer makes a mildewproof caulk. Here are several of the major players. Remember, look for the words "mildew-proof", not mildew-resistant.

Multi-Colored Mildew-Proof Caulk

Would you like mildew-proof caulk in a color other than white? Polyseamseal makes it. They also specially blend colors to match Kohler Plumbing fixtures.

If you see "Kohler" brand caulks look closely on the back label and you will see the Polyseamseal name. The colors are prefect matches! You can use them for non- Kohler fixtures as well.

Related Articles:   Caulk Removal,  Create Caulk Joints,  Mildew-Proof Caulks

Creating the Perfect Caulk Joint Every Time

On a recent trip, I observed a caulk joint in an airport bathroom. The person who applied it - I am convinced - used his big toe to smooth the joint. There was caulk 3/4 of an inch on either side of the 3/16 inch wide crack!

Getting the Tools Set Up

All too often people start to caulk with just the caulk tube and the caulk gun. They cut the tip and get going. Big mistake! If you are using a water based caulk, you need to have a bucket of clean water, some rags, a grout sponge and possibly some paper towels. If you are using silicone caulk, you will just need lacquer thinner and some rags.

The water and/or lacquer thinner are important. These are the solvents needed to wash away the smears from either side of the caulk joint once it has been tooled.

Suggested Tool List

Disappearing Chemicals

My research for this column was fascinating. I talked with two caulk scientists. I found out that caulks contain mildewcides and fungicides. These chemicals happen to be water soluble. This means that water can dissolve them.

I also found out that even though caulk appears smooth to the naked eye, it is actually a somewhat porous surface where mildew spores can readily hide. Couple this with the fact that many body soaps contain ingredients that are food for mildew and you often have lots of water where you have caulk and you end up with perfect growth and survival conditions for mildew.

Caulks that mildew quickly contain small amounts of the mildewcides. Mildew-proof caulks contain lots of these chemicals. The intention is to add enough mildewcide such that it takes years for it to completely wash away from the caulk. The manufacturers hope that it is time to re-caulk before the caulk actually begins to turn black. I don't have any problems with that thought process!

Getting Caulk to Stick

Caulks are basically a first cousin to adhesives. Caulk, adhesive and paint chemistry is very similar. Stop and think. All three things basically 'stick' to something. If you want caulk to be waterproof, you need to make sure that the surfaces to be caulked are clean. They need to be dry.

It is usually not a problem to get caulk to stick to a crack. If a caulked joint does fail, the trouble can often be traced to dirt or dust that was not removed prior to the application of the caulk. Take time out and always clean the areas to be caulked.

Caulk Removers

If you visit a large home center or a major paint or hardware store with a good caulk department, you will often find caulk removers. These products work well if you follow instructions.

Often the largest hurdle is removing as much of the caulk as possible - with a razor or some other tool. The more caulk you can scrape away before applying the remover the better off you are.

You can often find caulk removers for each type of caulk. However, the tougher the caulk - like silicones - the harder they are to remove. One of my readers wrote to me just before this bulletin was written - a woman from Michigan. She reported to me that she had great success with a silicone caulk remover made by the 3M Corporation. I have not used it so I can't tell you what I think about it. The Michigan reader told me that she used it to "...get silicone caulk off our fiberglass trailer and it worked GREAT!" She convinced me!

Preventing Mildew in Baths

An ounce of prevention is worth a pound of cure it is said. This is true in bathrooms with respect to the war on mildew. You can reduce mildew growth in tubs and showers if you try the following things:

Keep the tub and shower surfaces clean. This means that you should wash them once or twice a month, not once or twice a year! The soap and body oils that come off of you are mildew food!

Consider using a squeegee in the tub or shower. Just after you turn off the water and before you jump from the bathing area, use it to remove 90 percent of the water from the tub and shower area. This water will go down the drain instead of evaporating into the air during the rest of the day. High moisture air content within the bathroom helps the mildew to live.

Leave the shower door or curtain OPEN after you leave the bathroom. Also leave the bath door open so that air flow can readily dry tub and shower surfaces. You want the mildew to die of thirst!

Related Articles:   Caulk Removal,  Create Caulk Joints,  Mildew-Proof Caulk Manufacturers

Caulking Techniques & Tips

Every successful job depends upon having the right material for the job and the right tools to install the material properly. Common sense dictates that if you attempt to install a quality product with inadequate or inferior tools, you will achieve less than excellent results. Caulking is no different.

Before you start your caulking job, take inventory of your caulking "tools." Here is what you should have: high quality cartridge caulk gun, putty knife, scissors - knife - or razor blade, 5 inch long piece of thin, rigid wire, back up filler strip (for those deep cracks in excess of 1/2 inch deep), clean dry cloth, rounded synthetic sponge and bucket of warm water (if using a water based caulk), or correct solvent (if using a solvent based caulk.)

Just like anything, there is a right and a wrong way to caulk. The first thing to do is to make sure you have purchased the right caulk for the right job! Determine this by carefully reading the label on the caulk tube. Make sure that it says on the label that the caulk will stick to what you are caulking. If in doubt, ask for some help. Don't "hope" that it will work.

Once you have the right caulk, read the directions on the label. Yes, I know this sounds boring. I mean, really, who has those extra two minutes it's going to take to do this? Do you think it is worth two minutes to ensure a first-class job? I thought so.

Water based caulks can often be applied to wet or dry surfaces. Non-water based caulks, especially silicone, will not remotely stick to wet or damp surfaces. The trick to a successful job is taking your time. All too often, people squeeze the heck out of the gun and caulk squirts out all over the place.

The key, in my opinion, is the right size hole in the tube. Trim the nozzle of the tube a little at a time. Remember, you can always trim the tube a little more. There is no way of reducing the hole if you cut off too much. I always make the hole of the tube about 60 to 70 percent the size (width) of the crack I am trying to fill. Depending upon weather conditions, caulk only two or three feet of the crack and stop. Tool the joint with your finger and wipe the excess caulk onto a paper towel.

The next step, if you're using a water-based caulk, is to tool it with a damp grout sponge. Get a sponge wet and squeeze out all of the water you can. You wipe the joint you just tooled with your finger to remove EXCESS caulk you smeared on either side of the actual crack you caulked. This is the step MOST PEOPLE SKIP.

Don't skip it. Don't press too hard with the sponge and make repeated passes along the joint until you just see caulk in the crack. This works well when caulking cracks indoors along smooth objects.

You can't do this if you're caulking up against a rough surface like stone or brick.

If you apply the perfect amount of caulk, there will be no excess when you tool the joint. This is very difficult to do. I know of only two or three painters who really have perfected this science. However, once again, the key is taking your time. Simply slow down, and squeeze the gun slooooowly. This is especially critical if you are caulking against a rough surface such as brick. If you get excess caulk on brick, it is almost impossible to remove. Caulk, remember, is like glue! It sticks very rapidly to things. You can make a big mess on brick if you are not careful.

If you have never caulked before, buy a tube (caulk is really very inexpensive) and experiment! Nail a few different sized scrap boards together and caulk the seam or the corner of the overlap. Simply imagine that you are caulking a new window edge against a piece of trim.

Silicone caulks are a challenge. Take your time and use lacquer thinner to tool the joint. Ventilate well, if indoors!

Caulk Manufacturers

• Bostik
• DAP Inc.
• Liquid Nails
• ITW TACC Miracle Adhesives
• NPC Colored Sealants
• OSI Sealants, Inc.
• Red Devil Inc.
• Sashco Sealants
• Degussa Sealants
• 3M

Two Basic Types of Caulk

There are two basic types of caulks in use today: water based and non-water based. Each type has distinct advantages and disadvantages. Within each grouping, as you might imagine, there are various sub-groupings.

One thing the two basic types do have in common, however, is the fact that chemically speaking, they are closely related to adhesives. This makes sense when you think about it, as the caulks usually are quite sticky when you apply them. Also, when you select the right caulk and apply it properly, it has a tendency to stick to the item you apply it to for quite some time. In fact, some caulks are formulated to be more of an adhesive than a caulk. My guess is that you have seen tubes of "adhesive caulk".

Water Based Caulks

The latex caulks that many of us are familiar with use water as a basic ingredient. The presence of water in the caulk is an advantage if you are interested in clean-up and workability. It is a disadvantage if you are looking for extremely long life.

Often, these caulks have primary ingredients, which add to their flexibility. Commonly, latex (basically synthetic rubber) and acrylics (highly flexible plastics) are found in these caulks. Once again, my guess is that acrylic, latex caulk rings a bell with you. Caulks need flexibility, as they are intended to bridge gaps between things that commonly move.

Silicone can be added to a water based caulk in small amounts. By doing this, the flexibility of the caulk is increased. These are the caulks you frequently see advertised as siliconized acrylic latex caulks .

Caulking technology has created specific water based caulks for specific jobs. This is a distinct advantage. The caulks have been formulated to give you maximum performance depending upon the job you are going to undertake. Almost every manufacturer clearly prints on the caulk tube label just what that caulk will caulk best. I highly recommend that you read the labels first before buying them and using them. This will ensure maximum performance and satisfaction on your part. Try to break the habit of reading the label after a problem has developed!

Non-Water Based Caulks

There are several widely used non-water based caulks. However, most homeowners are only familiar with one of these, that being silicone. The other two widely used caulks in this group are urethane and elastomeric caulks.

Silicone caulk has won widespread acceptance by many homeowners. However, it can be difficult to apply. Some silicones can cure quite rapidly, making for messy application jobs. Also, because they stick sowell to many non-porous objects, removing excess silicone can be difficult. Virtually everyone knows that paint will not adhere to pure silicone caulks. Well guess what? In many cases, silicone caulk will not adhere to previously applied silicone! This means that your first application must be your last. You have to get it right the first time!

Urethane caulks have been used by commercial builders for years. These caulks offer unbelievable flexibility. Some of these caulks can withstand up to 50 percent movement in the caulked joint! These caulks are difficult to work with, however the work is well worth it in many cases. Often you need to use solvents, such as mineral spirits or lacquer thinner to tool the joints. I have used caulks like this to caulk expansion joints in masonry with tremendous success.

Elastomeric caulks are non-water based caulks which have both interior and exterior applications. They tend to exhibit more adhesive type qualities. For the most part, they are not nearly as flexible as the urethane caulks. Tooling and cleanup require the use of solvents, just the same as the silicones and urethanes.

Advantages

Because the non-water based caulks are tougher to work with, they must offer something in return. These caulks offer superior durability, flexibility and adhesive strength unobtainable from the water based caulks. Many of the non-water based caulks cure quite rapidly. This allows them to come into contact with water soon after they are applied. This water rarely, if ever, harms the caulk.

It shouldn't surprise you that the non-water based caulks are more expensive. The ingredients which give them their positive qualities simply cost more. Water, on the other hand, is very inexpensive.

When faced with that next caulk job remember to take your time. Think about how much time you are about to spend. The little extra money for a high quality caulk and the extra time spent applying it may pay huge dividends! Don't always opt for the easy way out. Good luck on your next project!