T.I. System # 3800
Suggested Use Procedures
- MELTING POT TEMPERATURE SETTING AND AGITATOR R.P.M.
- Pot thermostat should be set and held constant at 440°F +- 5°F.
- Discharge valve should be set at least 100°F hotter (540°F +- 5°F) and should be left on at all times to avoid it freezing up.
- Agitator should travel at approximately 20-25 R.P.M
- MELTER MAINTENANCE
- Melter should be checked frequently against burned out heater strips, as well as proper thermostat operation.
- Valve heaters and thermostats should be checked for proper thermostat operation.
- Melter should be cleaned at regular intervals (six months to one year) to eliminate contaminate buildup on the screen and in the sump.
- CHARGING MELTER WITH T.I. SYSTEM COMPOUNDS
Remelt material is generally not recommended, however, a minimum of 50% new powder must be added to any remelt blend. If a high humidity condition is present, remelt is definitely not recommended. Conditioned use of only remelt material will always result in an overload of contaminates, causing increased melter maintenance, lowered physicals on finished mandrels, and general dissatisfaction of pour consistency and texture.
CAUTION: ALWAYS WEAR HEAVY HEAT RESISTANT GLOVES, FACE MASK AND EYE PROTECTION, ALONG WITH ARM SHIELDS, HEAT RESISTANT APRON, FOOT AND LEG SHIELDS.
MOLTEN MATERIAL CAN CAUSE SEVERE BURNS!!!!
- CASTING PROCEDURE
- Stabilize tool or mold at "Preheat " temperature. This may be done in oven, or using heat lamps or gun. A simple method is to fill tool with casting material and leave for a period of time and then remove. This will usually provide sufficient heat to eliminate pour lines and chill imperfections.
- Casting material from melter discharge valve directly into mold is not preferred, as air entrapment is almost always present. Rather, use of a steel pail or other suitable container to transfer material from melter into a pail then stirring gently to remove air bubbles that may be present prior to casting into mold.
- SOLID CORES:
When casting T.I. System compounds in mold, always try to "slide" material down the side of the mold. This means the mold must be tilted at the start of the pour and then gradually moved back to an upright position as the mold fills. If the material is poured directly into an upright mold, the casting material will splash when it hits bottom and cause serious imperfections. Pouring technique is only accomplished by practice and by following these simple guide lines. After casting material has solidified, do no wait too long to demold, especially if the part has complicated geometry, as thermal contraction may cause difficulty in removal, as well as possible cracking. Usually 5-15 minutes is sufficient. Large parts will require an additional 5-10 minutes. In any case, demold time must be monitored for each different part.
- HOLLOW CORES:
Producing hollow cores is easily accomplished. First the timing will be different with a metal tool than with an epoxy laminate one. Starting with the epoxy tool, fill the mold full the same way as outlined for solid cores. Make sure that the mold has sufficient preheat before casting. When mold is full, wait 60 seconds on an average size tool, and about 3-5 minutes on a larger tool, then pour material out of mold back into melter or pail and wait 5-10 minutes, leaving core in mold. This will usually produce about a .250" wall thickness. A good rule of thumb to remember is a .250" wall thickness every 30 seconds. If a greater wall thickness is desired, repeat the same procedure for an extra .250" thickness required. Timing is very important because in most every case, leaving the mold full of molten material too long will result in uneven core thickness. Now, using aluminum tooling, the tool should definitely be preheated to eliminate pour lines. With either type of tooling, the material should not be poured more than 575°F, otherwise, the dwell time will be too long to solidify and in addition, cause an uneven wall thickness.
Ideally, a log should be kept on each tool as proper dwell times are achieved, keeping in mind that constant pouring temperatures are very important and must be maintained.
- FINISHED MANDRELS:
Completed mandrels may be placed in poly-bags of any mil thickness (preferably .006) for storage. The need for oven storage is not required. Room temperature storage is preferred, and when ready for lay-up, may be heated to facilitate faster lay-up with prepreg materials. Barrier coatings are recommended and should be applied to bare mandrels prior to lay-up.
We recommend Miller Stevenson (MS143DF) as it acts as a barrier coat and a release agent combined.