plating, anodizing, & finishing Q&As since 1989
How to fix porosity in an aluminum mold for roto-molding
October 18, 2010
Just looking for some insight into how I might fix/fill some porosity holes in a sand cast aluminum mold I am currently using for rotomolding plastic parts.
It seems after a few attempts at sand casting our mold we still can't escape the porosity from showing up after we've finished polishing the mold and it's leaving a pretty undesirable finish on our rotomolded parts.
Is there a good (preferably cost effective) solution to filling in all the showing porosity holes, and/or putting some sort of smooth coating on the aluminum mold to finish it?
Boat manufacturer - Kuala Lumpur, Malaysia
October 27, 2010
WE have thermally sprayed Aluminium onto cavities, holes of cast moulds. thermal input less than 80° C.S.Guna
- Shah Alam, Malaysia
December 11, 2010
Depending on geometry of surface, wall thickness, number and depth of pores and other relevant parameters additional options to the ones already mentioned may include:
A) Same metal than mold:
1- Micro TIG welding with aluminum rod
2- ESD welding with Al rod
B) Different metal than mold:
3- Brush plating with special Ni+alkaline Cu+acid Cu+Ni
4- Conventional electroplating (cyanide+acid Cu+Ni)
5- Alkaline EN+acid EN+acid Cu+EN.
Intermediate and final dressing of surface will most surely be required.
Monterrey, NL, Mexico
December 12, 2010
Thanks for the responses guys, lots to think about.
Thanks again guys.
- Kuala Lumpur, Malaysia
December 14, 2010
Just to add another possibility you could consider vacuum impregnation to fill the porosity before plating to give your final finish.Brian Terry
Aerospace - Yeovil, Somerset, UK