Renovating a Hardinge HLV-H

[BillTodd]

I got mixed result from my second attempt... :(

The small door has come up really well (I'd only given it a quick coat before I'd run out of paint). The second coat on the head and bed are fine . The stand is OK

However. The electrical door, tail stock and power feed box have all pickled into a crinkle finish and parts of the table have also a hint of it.

I'm not really sure why; perhaps the underlying paint was not properly dry, perhaps it was on too thick. :confused:

I'll live with the table top, but I'll have to wait for the paint to harden before I can rub-down and re-spray the other bits.

I'll take some pictures of the head/bed tomorrow. Meanwhile, here's a picture of the reassembled carriage handle. (that odd blue line is a trick of the light - it's actually a very faint scratch that will easily polish out)

[aafradio]

I got mixed result from my second attempt... :(
However. The electrical door, tail stock and power feed box have all pickled into a crinkle finish and parts of the table have also a hint of it.
I'm not really sure why; perhaps the underlying paint was not properly dry, perhaps it was on too thick. :confused:out)

Ah yes...my favorite paint style (since I restore WWII aircraft radios which are almost universally finished in black wrinkle paint.) The wrinkle is caused by statistically random uneven paint film contraction between coats during the curing process. The wrinkle or crackle paints of the 1930s and 1940s were actually produced with additives and techniques that promoted the process between coats.

More to the point in your case, there are at least four elements I can recall that contribute to unintentional wrinkling:
1) too much paint film thickness in each coat (partially related to #3 below)
2) incompatible solvents or paint formulations between coats
3) incomplete curing (evaporation of solvents or crosslinking, depending on paint material) of a previous coat before a second coat is applied
and
4) temperature high enough to accelerate problems 1 through 3

What that means in a practical sense is to make sure the solvents of multiple coats are compatible (e.g., water based and oil based following coats are not a good idea, though they often work fine if enough time is allowed between coats), wait long enough between coats, avoid drying heat lamps unless you are sure of the other factors, and keep the film thickness reasonably thin.

It seems sorta ironic thinking about the reverse of the finishes I try to achieve, but the basic principles are fundamental to both results.:)

-Mike