Filling casting blow holes.

[Rik ShawParticipant @rikshaw]

[Rik ShawParticipant @rikshaw]

Yesterday I took the die grinder to some small blow holes on this casting then filled the silvery dimples near the pen tip with UniBond repair power epoxy metal. Today it had hardened nicely so I proceeded to smooth the stuff down. As soon as I got to the level of the casting the stuff in the dimples just fell out.

Now I am not sure if this stuff is unsuitable for filling these shallow dimples or whether a different product would "stick" better to the bare metal. Maybe I should have given it more chance by drilling some small holes through the dimples to give a better key. I made sure the dimples were clean and oil less before I filled them by wiping with isopropyl alcohol. In hind sight I think it would have worked better if I had just filled the holes without grinding them.

If you have used filler in similar circumstances in the past and it "stuck" OK I'd like to know what you used.

Rik

[JasonBModerator @jasonb]

For cosmetic filling I tend to use Upol "Extra" which seems to stick well and work for shallow as well as deep blemishes. If its a bit more strutctural then JB Weld is good but takes a bit more sanding. This is the Upol applied and then after sanding

For just pin holes which show up once the primer is applied the one part surfacing putties work well, Squadron White putty is one I use. this is before and after the putty

I probably would not have bothered to grind out the holes.

Edited By JasonB on 20/06/2014 16:44:49

[Bob Brown 1Participant @bobbrown1]

I think I would use an epoxy based product like this **LINK**

Bob

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