It depends on the product. Some are solvent based and some are water based. Best practice is to read the product label to determine if cleaner/remover is required or if water or acetone will work.
All good advice above. Also, you never want to weld over a crack, as mentioned excavate it, inspect it visually and if found by Liquid Penetrant use LP to make sure none of the crack remains. Typical inspection criteria is for no linears, visually or by LP. Welding over will probably leave an internal notch with potential for subsequent issues. The idea that it is acceptable to weld over any defect is "an old wives tale" which can put you on the road to disaster. I'm involved with weld repair of castings on a day to day basis. I would excavate, make certain that the root of the excavation is radiussed and the sides tapered out to >30 degrees per side, LP the cavity, more than likely it is a solvent removable penetrant, so after the cavity is clear I would clean with solvent or the appropriate cleaner per the instructions, then weld. In the event of access issues do the best you can or pull the component out to repair. One other thought, what is the temper condition of the casting? Alumimum goes back to the annealed state in the HAZ when welded. Good luck.
as said before drill out the crack, or it will never be removed & it will propagate further.
also like meteng said the cleaner is enclosed with the kit.
preclean, die penetrant, cleaner, then developer.
Mfgenggear
if it can be built it can be calculated.
if it can be calculated it can be built.
