Hydraulic fluid in keel tank

[charleskaluza@gmail.com]

Thanks for the feedback.

The marine surveyer seems happy now.

Hydraulic system was test run last week, the charge pump needed to be reversed but otherwise everything ran well. No perceptible noise but no load.

Hope to get the boat wet this summer.

Charlie

Live more Die less

[Jesse]

Greetings to all. My memory isn't what it used to be but I think an aircraft hydraulic fluid called skydrol was non flammable. This may be what Alan was dealing with. Very interesting thread. Jesse

[GordMay]

There are conditions under which Skydrol will burn.
Skydrol fluids are "fire resistant."

Traditionally the term "fire resistant" has been used to describe phosphate esters, as opposed to mineral oil based hydraulic fluids, because they are very difficult to ignite at room temperature. In standardized testing, a fine mist spray of Skydrol cannot be ignited with a burning propane torch. The same fine mist spray of a mineral oil hydraulic fluid, such as MIL-H-5606 or MIL-PRF-83282, produces a large fireball when touched by a propane torch.

The basic parameters of fire resistance include: 1) resistance to ignition, and 2) resistance to propagation of the flame from the source of ignition. The test methods followed by the industry are described in AMS 3150 and various ASTM test methods. For more detail, please ask for our Publication No. 9118 on fire resistance.

Skydrol fluids must be heated to high temperatures before they will sustain combustion. The fire point of Skydrol LD-4, for example, is 360oF. This is the temperature the fluid must be heated to in order for it to be ignited in the ASTM D92 cup apparatus. The autoignition temperature of LD-4 is 880oF. This is the temperature at which the vapors will ignite spontaneously.

[hellosailor]

BigCat, I think that 46 USC is irrelevant here, it regulates COMMERCIAL shipping and commercial vessels carrying passengers for hire. Recreational vessels, aka yachts, are always regulated differently and to a lower looser standard.

[BigCat]

"Recreational vessels, aka yachts, are always regulated differently and to a lower looser standard."

I know that CFR 46 is for commercial vessels. That would be my point. In commercial vessels, diesel tanks may be built in metal and solid frp boats, but gas tanks can't.

You have to get the full context when quoting US boat building law, because in another section it will tell us more about what they are describing-gas powered boats, open boats, etc. This fact makes reading the law quite difficult-I have seen a law reference another, that references another, etc., until you feel quite dizzy trying to get to the bottom of the matter.

[BigCat]

PS. At Skookum boat builders, where I learned fiberglassing 101 long ago, they made built in tanks for both water and diesel, but they always put in an extra layer of resin/reinforcement in the bilge where there was to be a tank, and then gel-coated the inside of the tank.