Hot knife

[D Yuniskis]

Hi,

[Obviously, the weekend has been spent disassembling
and repairing/replacing a variety of "toys" :-/ ]

What tricks can be brought to bear disassembling
plastic items that have been solvent welded (or glued)
together IN A COSMETICALLY ACCEPTABLE MANNER?

I typically use a heated exacto knife to slice the
item on the apparent "seem/weld". But, this is
time consuming, wasteful of energy and still doesn't
leave very "clean" results.

I've looked into purchasing a *real* "hot knife" but
I suspect they don't have the thermal mass to deal
with items as massive as most plastic enclosures (?)

 

[Geoffrey S. Mendelson]

What tricks can be brought to bear disassembling
plastic items that have been solvent welded (or glued)
together IN A COSMETICALLY ACCEPTABLE MANNER?

I've had good luck with ham radio battery packs for handhelds by freezing them
and then hitting them on a stone step. The welds crack open.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel [email protected] N3OWJ/4X1GM
New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or
understanding, as in he has a sub-wikipedia understanding of the
situation. i.e possessing less facts or information than can be found in
the Wikipedia

 

[N_Cook]

Hi,

[Obviously, the weekend has been spent disassembling
and repairing/replacing a variety of "toys" :-/ ]

What tricks can be brought to bear disassembling
plastic items that have been solvent welded (or glued)
together IN A COSMETICALLY ACCEPTABLE MANNER?

I typically use a heated exacto knife to slice the
item on the apparent "seem/weld". But, this is
time consuming, wasteful of energy and still doesn't
leave very "clean" results.

I've looked into purchasing a *real* "hot knife" but
I suspect they don't have the thermal mass to deal
with items as massive as most plastic enclosures (?)

Squash, long ways first, in a carpenters vice usually splits enough in the
middle of the run, to make a start, and then blades. If nothing seems to be
happening , before you chicken out, try diagonally or short ways. Sometimes
will make a small tear into the cosmetic area but I've never had a full tear
into the fare surfaces. Somtimes distorts internal heatsink if up against
the case

 

[Allodoxaphobia]

I've had good luck with ham radio battery packs for handhelds by freezing them
and then hitting them on a stone step. The welds crack open.

In the same vein, I try the freezing and then use an old wood chisel and
a light mallet along the seam. Sometimes it takes several passes around
the weld. The last bit is usually done with a thin, wide knife blade.
The corners -- if any -- can be the toughest...

GL
Jonesy

 

[D Yuniskis]

I've had good luck with ham radio battery packs for handhelds by freezing them
and then hitting them on a stone step. The welds crack open.

Hmmm.... I was just about to tackle a small UHF transceiver.
I'll try that (if it doesn't work, I can always trash the
thing :< )

 

[D Yuniskis]

Hi,

[Obviously, the weekend has been spent disassembling
and repairing/replacing a variety of "toys" :-/ ]

What tricks can be brought to bear disassembling
plastic items that have been solvent welded (or glued)
together IN A COSMETICALLY ACCEPTABLE MANNER?

I typically use a heated exacto knife to slice the
item on the apparent "seem/weld". But, this is
time consuming, wasteful of energy and still doesn't
leave very "clean" results.

I've looked into purchasing a *real* "hot knife" but
I suspect they don't have the thermal mass to deal
with items as massive as most plastic enclosures (?)

Squash, long ways first, in a carpenters vice usually splits enough in the
middle of the run, to make a start, and then blades. If nothing seems to be
happening , before you chicken out, try diagonally or short ways. Sometimes
will make a small tear into the cosmetic area but I've never had a full tear
into the fare surfaces. Somtimes distorts internal heatsink if up against
the case

Ouch! This seems more likely to yield a *mess*...

 

[D Yuniskis]

Hmmm.... I was just about to tackle a small UHF transceiver.
I'll try that (if it doesn't work, I can always trash the
thing :< )

I tried freezing and then wacking with a hammer (i.e., as
if trying to dislocate one side of the weld from the other).
No good.

I'll try a sharp wood chisel on the seam next.

Then, resort to the heated knife. :<