Air caulking gun for seams???

[Clyderigged]

I will be hopefully finishing up refastening the hull of my Tahiti Ketch after replacing a majority of the frames. I have reefed out a majority of the seams, topsides and underwater, and will be applying seam compound soon.

It has been suggested to me that using an air driven caulking gun instead of a regular caulking gun or putty knife will DRAMATICALLY cut down on the time and effort of shooting the seams.

Anyone have any experience with this and any suggestions on feed rates, pressures, types of guns/ tubes, etc will be greatly appreciated.

Cheers,
Jamie

[Dave Fleming]

Jamie, who gave you that advice?

[JeffH]

Actually, I have used a caulking gun to pay hull seams before. However, it involved a propane burner, a large pot of water, about a dozen cans of standard Interlux seam putty (white topsides and brown underwater), and refillable caulking tubes. It worked pretty well, but I wouldn't recommend it to the faint of heart. Somehow, I don't think this is what the original poster had in mind, though.... *sigh*

Jeff

[Dan McCosh]

I have used air-powered caulking guns. They are basically difficult to control, particularly to shut off. Also the air--pressure tends to be marginal, believe it or not, for propelling the caulking. I also have used several motor-driven types using a power drill as power. These are far superior. Unfortunately I don't remember the brand name of the one I'm using now. These use a screw-jack driven by the drill to push the piston. We caulk about a thousand feet of seams some Springs, and this can wear out your grip with a hand-driven gun. I think someone is making a similar gun with a built-in drive and a rechargeable battery. With two people working, one with the gun an one with a putty knive following up, this is the way to go.

[Dave Fleming]

Sigh, there I go again...not reading the post completely before opening mouth. redface.gif
I had the impression ( WRONG Dave ) that Jamie wanted to actually cork the seams with the tool.
Instead, after reading the replys and re-reading the original post, comes the dawn! redface.gif

David slowly slinks back into his Rum bottle making sure to insert the cork after him. ;)

[Clyderigged]

Dave,
Got the advise from a boatwright working at the yard in San Rafael where i am on the hard.

How would you suggest to accomplish putting the seam compound in? Putty knife or manuual gun, both, or ???

Thanks again,
Jamie

[Dave Fleming]

Gosh Jamie, I have no experience with such tools.
Seems like Dan has had some.

Puttying seams is tedious work so if the tool works correctly it just might be the way to go.

Gonna be a learning curve with it, be prepared for that.

[Chris Gerkin]

I used an air gun with a 2 part boatlife caulk. Messy but the work went quickly. My compressor is 5 horse.

[Clyderigged]

Dan,

Are the motor driven guns pneumatic or electric that you have used with success?
Even though my hands are used to splicing wire rope and turning in wire seizing, squeezing a caulking gun’s handle for extended periods of time really cramps my hand. ;) :D ;)

Dave,

Is the standard method to use a hand caulking gun followed by a putty knife or just using a putty knife to apply the compound. I plan on using brown Interlux for the bottom and white for topsides seams.

Jeff,

How warm / hot did you have to get the seam compound to make it go into the tubes? Did you place the cans in warm or boiling water to facilitate packing the refillable caulking tubes?

Thanks to everyone for the help,
Jamie

[Dave Fleming]

Jamie, I am an old white or red lead putty type.

[JeffH]

Originally posted by Dave Fleming:
Jamie, I am an old white or red lead putty type.smile.gif Ditto

Yes, if you actually want to try this, the cans of putty were heated in the water. The water was, preferably, hot but not boiling, since the putty turns to a very runny liquid at higher temperatures. Then take putty that has reached nice, fluid (but not TOO fluid) consistency and spoon into a fillable caulking tube. Rapidly load tube into caulking gun and start squeezing into the seam like you would with any normally liquid seam compound (like Boatlife, Sikaflex, or whatever). Be VERY CAREFUL with the first couple squeezes, since the putty tends to cool and stiffen in the tip during the time it takes to load the tube and get it to the boat. If you squeeze too hard, you'll get a few inches of seam puttied, and then there will be a torrent of hot seam compound shooting out all over everywhere. If you've managed to succesfully fill some seams, run over them with a putty knife while the putty is still soft (if the putty presses back up slighly convex in the seam, the seam is full. If it doesn't, put more in).

All in all, this method was faster and had much less waste than just going at a hull with a can of putty and knife; however, there was a lot of trial and error involved. Like I said, not for the faint of heart ;)

Jeff

[Dan McCosh]

The power caulking gun I use is powered by an electric drill. I've used both battery and cord drills. It drives a piston via a kind of screw jack. The caulking feeds when you pull on the drill trigger, and it is stopped by pulling a lever that quickly disengages the screw.
I feed in the caulking, then follow up with either a putty knife, or often just push on it with my gloved finger to get it down in the seam and get any trapped air out. As I said, there are some similar models that have a built-in motor (I think Milwaukee makes one). They are a little more compact, but also more expensive. I think Woodenboat also lists one, but I tried that once, and it was a tad weak. Sorry I don't remember where I got the one I have, but I think I found it on the internet by searching power caulking gun.

[Keith Wilson]

Milwaukee indeed makes motor-driven caulking guns, which you can buy from Northern (http://www2.northerntool.com/cat-1/97+766791.htm), among other places. It seems an electric one would be easier to contol than one run off of compressed air, although heavier and lots more expensive. I have never used one, but using a hand gun for very long is a real pain.

http://www.northerntool.com/images/product/images/M0275_lg.jpg

Here's a cheap air gun:
http://jcsonlinetoolshed.com/shopimages/products/normal/AST405.jpg

[ 03-03-2005, 03:53 PM: Message edited by: Keith Wilson ]

[Dan McCosh]

Re: air guns. The problem I had with an air gun is that it builds up pressure to push the caulk out, and then it starts coming out too fast. You can't easily back off on the pressure inside the gun, as it is compressed in a chamber and wan'ts to keep expanding. The feed rate on the electric ones is controlled by the drill speed--when you back off, it slows more quickly than with the air gun. Otherwise, air is lighter and cheaper, although you also have to have a compressor on site.

[Dave Fleming]

Hint:
When I was first exposed to air tools the yard had these smallish valves on the air hose about 6 feet from the connnection to the tool.
IIRC they were referred to as 'painters valves'.

With this valve one could tweak the air pressure before it entered the tool and not just depend on the throttle control on the tool.

Worked awful slick. One of the nice things about air tools is that there is no coasting after the throttle is released.

Dunno if that helps in this application but, just fuggered I would throw that out for chewin' on.

[Dan McCosh]

An air caulking gun isn't like most air tools. It doesn't have moving parts. It's basically a cylinder that holds the cartridge, with an air valve at one end. The air is compressed behind the caulking cartridge, and the air drives the caulking out the tip. This leaves a reservoir of compressed air between the trigger/valve controlling the air and the caulk. This is what makes it tough to stop the flow quickly. It gets worse when you let in air and the caulking is a little stuck, then it lets fly when it finally moves. They probably work OK if you have long, continuous application--a big window, maybe deck seams, but I found it problematic for a boat hull.

[Dave Fleming]

Understood.