LIGO Document E1000386-v1
- Mass spectrometer (aka Residual Gas Analyzer, RGA) test results for MasterBond EP30-2 epoxy. This material is intended as a replacement for VacSeal (which is no longer available). In particular it is intended for use in the following aLIGO applications:
1) bonding stand-offs (aka prisms) to the barrel of masses for wire suspensions
2) bonding Acoustic Mode Dampers (AMDs) to the barrel of test mass optics
Use for any other application in aLIGO must be reviewed and approved by Systems.
For this qualification test the following steps were taken:
1. clean 6 microscope slides.
2. mix EP30-2 epoxy 1:10 by volume.
3. spread evenly over entire surface of slide, one side.
4. cure at room temperature for 24 hrs.
5. Vacuum bake 12 hrs at 50C for water bake off.
6. Take an RGA scan at Room temperature.
1) Although this test was performed on room temperature cured samples, according to the manufacturer the best cure schedule (yielding the strongest bonds) is an overnight (say 12 hr.) room temperature cure, followed by a heat cure of 3 hours at 66C (150F). Other acceptable cures include the elevated temperature cures cited in the data sheet (see link below):
a) 40°C (104°F) for 16-24 hrs, or
b) 100°C (212°F) for 2-4 hrs
2) A subsequent vacuum bake should be performed at just below the maximum service temperature (see data sheet) or 293F (145C) for 48 hrs. UNLESS DIFFERENTIAL THERMAL EXPANSION/STRESS CONSIDERATIONS FOR THE MATERIALS INVOLVED DICTATE A LOWER MAXIMUM CURE TEMPERATURE!
3) The samples for this test are representative of the "staking" done in the past for setting a standoff on a barrel, i.e. applying a small amount of adhesive along the perimeter. In contrast applications such as the AMD will use the adhesive in a thin bond with a long diffusion length. Consequently additional samples will be prepared and tested in this configuration (bonds between 1" diameter glass disks).
- approved by Dennis Coyne
Added the HxTS Magnet/Dumbbell Repair/Regluing Procedure Document, T1400217
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