Hylomar Universal Blue Gasket and Jointing Compound
Hylomar Universal Blue is a polyester urethane based viscous putty blended with a solvent to make it easy to apply, whether pumped, applied in a tube, or sprayed in an aerosol.
A non-setting sealant, it doesn't harden, even at 250°C. It has a unique curtaining action.
As flanges sealed with Hylomar Universal Blue are pulled apart, the material stretches, and then breaks cohesively, leaving sealant on both sides.
When the flanges return together, the putty reseals, a self-healing mechanism.
This makes Universal Blue a particularly effective sealant on close fitting large flanges which are subject to extreme vibration, distortion, or joint movement, because while the seal may break for a microsecond, it reseals and the fluids remain contained.
Hylomar Universal Blue is the world standard for a non-setting sealant. It is used by many of the worlds automotive manufacturers, major airlines, compressor manufacturers, heavy equipment manufacturers, various OEMs and racing teams. It is a polyester urethane based viscous putty blended with a solvent to make it easy to apply, whether pumped, applied in a tube, or sprayed in an aerosol. It was a revolutionary sealant when it was introduced over 40 years ago, a development product out of Rolls Royce that was used to seal the flanges in gas turbine engines and withstand the high temperatures and intense vibration of a jet engine. A non-setting sealant, it doesn't harden, even at 250°C. It has a unique curtaining action. As flanges sealed with Hylomar Universal Blue are pulled apart, the material stretches, and then breaks cohesively, leaving sealant on both sides. When the flanges return together, the putty reseals, a self-healing mechanism. This makes Universal Blue a particularly effective sealant on close fitting large flanges which are subject to extreme vibration, distortion, or joint movement, because while the seal may break for a microsecond, it reseals and the fluids remain contained.
Universal Blue is resistant to a
wide range of fluids, including all industrial fuels, oils, water
and brine, air, turbine and piston engine combustion products,
water, water/glycol and methanol mixtures, petroleum and synthetic
diester lubricating oils, gasoline, lubricating oils, gasoline,
kerosene fluids, and most fluorocarbon refrigerants. Hylomar Universal Blue can be used
to seal joint faces or threaded parts. It is effective for sealing
metal to metal and plastic to plastic. Typical applications include
water pumps, oil pumps, instrument inspection covers, cylinder
heads, oil sumps, intake manifolds, timing case covers, gear box
and transmission housings, and as a coating for pre-formed gaskets.
Hylomar Universal Blue can be used to seal joint faces or threaded parts. It is effective for sealing metal to metal and plastic to plastic. Typical applications include water pumps, oil pumps, instrument inspection covers, cylinder heads, oil sumps, intake manifolds, timing case covers, gear box and transmission housings, and as a coating for pre-formed gaskets, it also has tremendous vibration and noise damping properties.
Hylomar Advanced Formulation is a solvent free version of Hylomar Universal Blue. Advanced Formulation was developed twenty years ago as a response to pressures to eliminate solvents from manufacturing processes. Instead of using a solvent such as methylene chloride or acetone as a carrier for the Universal Blue polymer, Hylomar chemists found a silica-type mixture that was solvent free and yet still was easily applicable and retained the benefits of Universal Blue. Advanced Formulation (AF) does have some differences to Universal Blue. The curtaining effect (elongation) is not quite as large, so the gap fill is slightly reduced. On the other hand, the silica content raises the temperature resistance of the compound, and also provides a mechanism to continue sealing the joint at high temperatures even after the Hylomar polymer has burned off.
Advanced Formulation is now widely used in the automotive industry, particularly on gear box and transmission housings and flanges, where it is resistant to gear oils that attack silicones. AF is known to apply smoothly and easily without the maintenance issues and curing problems associated with silicones and anaerobics.
|Hylomar being applied to an axle housing and an exhaust manifold.|
You could say Universal Blue was an industrial precursor of the 3M Post-It Note". Non- setting sealants work by filling the imperfections between the joint surfaces. This stops any fluids leaking through the joint. The product has a low cohesive strength so that the joint can be opened easily. Much like a Post-It Note " Hylomar non-setting sealants permit joint movement, and even flange separation, but reseal the moment the joint returns to its normal position. This self-healing mechanism is at the core of how non-setting sealants work.
If you would like to experiment, try spraying the back of a poster with Hylomar XP Aerosol. It will then adhere to a wall or another surface, yet can be pulled apart like a Post-It Note.
Hylomar Universal Blue has higher adhesion, and will support more weight than a Post-It Note, but it works on a similar principle. Some customers have used AF to position metal pieces in place during assembly when they need to be re-positioned or adjusted later in the process. The temporary bond would hold the piece in place temporarily.
As Universal Blue is non-curing, it allows for easy disassembly and repair. Old Universal Blue can be just wiped off with a rag, paper towel (it works better with a solvent such as our Hylomar Gasket Remover) or Hylomar Grand Prix Wipes.
The application of Universal Blue is straightforward, which makes for simple manufacturing processes. There are no set times to observe, nor cure times to slow up testing or assembly. AF will not clog up nozzles or cure over a shut-down period. In fact, the shelf life of Universal Blue is extremely long. While Hylomar only warrants its product for two years, under proper storage conditions Universal Blue is known to last for very long times and remain effective.We have seen tubes from the 1960s that are still ok (although we do not recommend using or guarantee product this old).
AF has been noted to work at temperatures up to 350°C on certain applications. We hypothesize that the silica/Hylomar polymer mixture fills the tiny surface imperfections of these joints, and at high temperatures even after the polymer degrades (which starts to occur at temperatures above 250°C) the silica and residue remain as a film on the surface, which for close fitting flanges closes off the leak paths.
For example Hylomar Advanced Formulation has been used to seal
Hylomar AF sealed the exhaust manifold on this engine despite high temperatures.
|Grade||Pack Sizes||Thickness Of Residue (mm)||Surface Finish (Ra)||Temperature Range ( OC)|
|Universal Blue||40g tube||0.03||3.0 m (max)||-50 to 250 (-58 to 482 °F)|
Part No. HYL.UBLUE-100
|Racing Formula||75ml tube||0.03||3.0 m (max)||-50 to 300 (-58 to 572 oF)|
|Advanced Formulation||85g tube||0.03||3.0 m (max)||-50 to 350 (-58 to 662 °F)|
|0.03||3.0 m (max)||-50 to 250 (-58 to 482 °F)|
|Aerograde Ultra||75ml tube||0.03||3.0 m (max)||-50 to 250 (-58 to 482 °F)|
The information given in the above tables are meant as a guide only. Whilst to the best of our knowledge and belief it is true and correct HYLOMAR Ltd makes no warranty expressed or implied as to the accuracy of the figures.
What is Hylomar PL32, SQ32, and Aerograde? What about PL32M, PL32L, and PL32H?
"Hylomar is a sealant"
SQ32 was the original name of the R&D program at Rolls Royce that led to the development of Hylomar Universal Blue. PL32 was the original product name, and was available in Medium (PL32M), Light (PL32L), and Heavy (PL32H) grades. Hylomar Aerograde superseded these grades in 1985, but the references were retained in some specifications.
What is the difference between "PL32" vs "Universal Blue" ...
Originally there was only one version of Hylomar... which was known as
Hylomar PL32 (offered in Light, Medium and Heavy grades). Many years ago
there was a brief attempt to consolidate the various grades (Light, Medium
and Heavy) under one name which was to be called Hylomar "Universal Blue".
However, since so many customer specifications had been written and based on
the original name and part number of Hylomar "PL32", the manufacturer
decided to re-introduce the original name and part number although they
added the prefix "Aerograde" to the original PL32 number. Therefore, the
original formula of Hylomar is now offered two different ways...
1) Hylomar Universal Blue (available only in Medium grade)
2) Hylomar Aerograde PL32 (available in Light or Medium grades)
** Both products are the same exact formulation although the Aerograde is
the one that is certified to meet Rolls Royce aircraft approval
** There are also other new formulations of Hylomar that have since been
developed (Hylomar Advanced, Hylomar M, Aerograde Ultra). However the two
versions above are the original formula and original material... they are
just packaged and marketed differently.