Have (Sili)gun Will Travel

Weekend Projects department; digital illustration of a man holding a beverage and laying in a hammock

Laying down a bead of sealant can be a work of art for some and make a terrible mess for others. You can level the playing field with the use of a Siligun caulking tool — and smooth out the results.

By Bill Gehr / Photos by author

ost RV service technicians will tell you that a good caulking gun is indispensable. Just look around any RV and you’ll find countless places where a bead of sealant makes the difference between a watertight interior and one that is plagued with leaks. An ugly looking bead of sealant is not (or shouldn’t be) an option — and even though many sealants are clear or blend in with the exterior color scheme, poorly placed sealant stands out like a sore thumb.

Resealing the roof seams and accessory flanges, as well as other places throughout the exterior that have weathered over the years, should be part of a regular maintenance routine — so having the right caulking gun is paramount. There are many types of caulking guns on the market, from the simplest (and cheapest) to more elaborate models that provide better control of the sealant. There’s nothing exotic about a caulking gun, so inventing a “better mousetrap” didn’t seem like it was on the horizon. But someone has done it — and the tool is called a “SiliGun Compact 4” (siliguns.com).

common caulking gun with plunger fully extended and laid out next to a ruler

Siligun caulking gun laid out beside a measuring tape

There is quite a bit of size difference between the Siligun and a common caulking gun. The standard plunger sticks out around 9 inches from the gun and has a 23-inch overall length, which is less suitable for working in tight spaces. The Siligun measures 13 inches total — and when the spent cartridge is cut off, the length becomes even shorter. The smaller profile also fits your hands nicely and offers greater control when laying down a bead of sealant.

The professional caulking gun that I have used for many years is very high quality, but one of the things that made it difficult to handle was getting off the trigger and pushing the release button at the same time to stop the flow of sealant (still under pressure) to prevent gobs of goo from dripping all over everything. Naturally, this made it much more difficult to terminate a beautiful bead without leaving a clump of sealant. I can’t even begin to think how many tubes of caulking I’ve used in 51 years, and I’ve tried other caulking guns that supposedly stopped the sealant from running after you let go of the lever. However they really didn’t work — and it’s difficult to restart a bead of sealant.

The Siligun, on the other hand, is a game changer. It’s much more compact than a standard caulking gun and the ABS plastic frame is much lighter. Coupled with those attributes, the non-drip feature solidified the deal. And, since there is no long plunger handle to deal with, it’s much easier to get into tighter spaces. It uses standard 10-ounce cartridges — and as the sealant is depleted, the back portion of the tube can be cut off to make the gun even smaller. With a full tube of sealant loaded into a standard caulking gun, the plunger handle sticks out about 9 inches for an overall length of 23 inches, which is not great for tight spaces. A loaded Siligun measures only 13 inches total.

Loading the Siligun for the first time may seem a little awkward, but after a few tubes the process seemed much more natural. To load the cartridge, the tip is cut off and the clutch lever is pulled back all the way while the tube is pushed into the gun until it’s seated against the cutter.

The blade built into the barrel cuts the tube as the sealant is dispensed. It cuts well but takes a little more pressure to squeeze the handle. You’ll acclimate quickly.

At first, I was a little skeptical about the plastic frame, but I was pleasantly surprised how well it performed and conformed to my hand. The 10-ounce tube of silicone rubber needed for the test RV repair was, at first, a little difficult to load from the front of the gun and push against the cutting blade — which splits the tube as the sealant is dispensed — but I quickly got used to it. The internal cutting blade does a good job of slicing through the tube, but it does require quite a bit of pressure on the trigger. Actually, once you acclimate to it, it only takes seconds to load/remove the cartridge and use the gun. I also liked the removeable tool for puncturing the membrane seal after cutting off the tip of the tube (it’s also good for clearing the nozzle after sitting in storage).

During a test, I cut off the end of the nearly spent caulking tube and was amazed how much that reduced the overall size. If you really need to caulk something in an incredibly tight space you could always squeeze out half the tube and cut the end off, but you won’t have much to hold on to when removing what’s left of the cartridge from the gun.

portion of the cartridge being cut off with a utility knife

If you’re working in tight spaces, the spent portion of the cartridge can be cut off with a utility knife. The only caveat: It’s more difficult to grab on to the remaining tube to remove it from the gun.

closeup of Siligun being used to lay down sealant

Laying down a bead of sealant was smooth and accurate. The anti-drip function is a game-changer. Once the lever is released the flow of sealant stops, eliminating the chances of leaving an unwanted glob at the end of the line. The Siligun is capable of dispensing latex, acrylic and silicone caulking.

When selecting a particular type of caulking, be sure that you read the directions — not all tubes will fit into the Siligun. It may be necessary to peel off the outside vinyl cover on some tubes.

The provided hook makes it easy to hang the SiIigun from a storage compartment rafter, although the gun’s diminutive stature also allows it to easily store in a toolbox or bag. Once you use the Siligun, you’ll have a fresh outlook when it comes to sealing projects — and since you won’t make a mess, the $19.99 investment (Amazon) makes it an even a better deal.

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