10/11/01

Liquid Radiator tests

Material compatibility test and adhesive bond strength tests 

Material compatibility tests

All materials used in the liquid radiator vessel and plumbing system should be
checked for material compatibility with the c5f12 liquid. Of specific concern is
compatibility with the carbon fiber plate, and the adhesives used to seal the
vessel. 

Compatibilty test with C5F12
1	take a sample of carbon fiber plate or other material
1.5 	clean sample using alcohol or other suitable cleaner.
2	Store sample in an environmentally controlled room for several days.
3	weigh sample, and measure the sample thickness
4	record relative humidity and temperature in the room
5	dry sample out in oven for 2 hrs at 200 F (or material max temperature
	if below 200F)
6	weigh sample and measure sample thickness
	this gives an idea of moisture absorption
7 	Submerge sample in c5f12 for 24 hrs
7.5	dry sample using a cloth, remove all excess liquid from sample. Do not
	dry sample using heat.
8	weigh sample and measure sample thickness
9	Continue soaking the sample in c5f12 for 7 days
9.5	Dry samples
10	weigh sample and measure sample thickness

Use a scale where a change in weight of .01% can be measured.
Where rubber gloves at all times, sample weights should not be contaminated by
fingerprints.

This test should be performed on Quartz, Carbon fiber plate, G-10 rod (1/4"
diameter), plastic tubing, stainless steel stubing (300 series), nitrile rubber
o-ring, a cube of epoxy. The test can also be performed on materials that will
be used inside the RICH tank superstructure. This will give an idea of 
compatiblity with c4f10 gas. Additional materials would be mylar, 
tedlar, polyureathane coated nylon, acrylic, nitrile rubber gasket material. 


Adhesive bond strength tests.

The adhesive bond strength between the G-10 stud and the quartz plate needs to
be studied. Also the bond strength between the G-10 stud and the carbon fiber
plate needs to be studied. Test to study the bond strength before and after
soaking in C5F12 should be performed

Make an adhesive joint of carbon fiber plate and g-10 rod. 
1	The quartz or carbon fiber sample size should be 3 mm thick and at 
least 1" square. Bond a holder to the sample so that it can be pulled
apart later. A section of aluminum shaped "T" bonded to the carbon fiber plate
has worked well in the past. The g-10 rod should be 1/4" in diameter 
and long enough so that it can be use to pull the sample apart later. All bond
surfaces should be cleaned prior to bonding.

2	The sample should be should be pulled apart without soaking in c5f12.
Several samples should be tested to get a statistcal average of the bond
strength.

3	Repeat process of making samples. Soak samples in c5f12 for several
days. Pull samples apart.

4	Compare the bond strength before and after soaking. 

5	Repeat tests using g-10 rod and the quartz plate.

To qualify the joint as a good joint, the stress in the joint should
exceed 680 psi. (pull force should be more than 33 pounds over a 1/4" diameter
rod). A moderately acceptable joint would hold about 11 lbs (1.22 psi static
head  times a cell of 3" by 3")