Anyone use clay dough to hold stuff while soldering? Wondering about long term damage

I did the exact same thing with some Play-Doh a couple years back when my clamp stand was in pieces, and I regretted it on the second or third session. After a few weeks the dough had gone stiff and left a greasy ring on the bottom of a project board I left sitting in it. It wiped off with isopropyl alcohol, but the spot stayed slightly duller than the rest of the finish, and I never fully trusted that board again after that. The oil-based stuff like plasticine is worse from what I've seen, it basicly never dries and just slowly weeps onto whatever it touches. Since then my go-to in a pinch is a folded piece of cardboard with notches cut in it so the board sits flat and the leads hang thru. Free, disposable, and it doesn't touch anything conductive. For holding a wire in place while I tack a joint I just use a short length of solid core wire bent into a hook, which is honestly better than any holder for awkward angles. I'd say the risk is less about months of corrosion and more about residue you have to clean before you can trust your joints. If it were me I'd keep the dough away from the underside entirely, even for a single session, and just prop the board on something inert instead.

I'll push back a bit on the dough being the villain here. I've used the same tub of kids' modeling clay off and on for maybe four years to hold boards flat while I work, and I've never had it mark or dull anything. The trick, at least in my setup, is that the dough only ever touches the board edges, never the underside where parts stick through. Anything sitting directly in the putty is asking for trouble, expecially the stickier craft putties that go greasy with age. If I get any residue it comes straight off with isopropyl and a cotton bud before I put the board away. My worry with dough is completley diffrent: it's too soft. When you poke a component through a hole or tug a wire to test a joint, the whole board rocks, and that's how you drag a hot iron across neighboring pads or end up with a cold joint. A holder needs to be rigid more than anything.

For anyone between stands, a small bench vise with soft jaws or even a block of wood with a couple of screws as stops has saved me more headaches than any squishy material. Cheap, solid, and nothing leaches anywhere.

My stand broke too, but I found a better fix than just propping the board. Instead of trying to keep it steady with some putty, I started using small C-clamps on the sides of my desk. I clamp the edge of the project board down, which locks the board perfectly in place while I solder. It's overkill for tiny boards, but for larger ones that need to stay flat, it gives me total peace of mind. I don't worry about residue or grease when the board is clamped down and secured. Just makes the whole setup more rigid.

I definitly agree with the person who said the greasy ring issue can really ruin a board's finish. It's annoying when you have to clean up something that just happens while you work. I use Blu Tack sometimes but only when I wrap it completely around the board using a small strip of masking tape so it doesn't touch any exposed copper or solder points. I learned that leaving it loose means the residue inevitably migrates into the seams of the finished project. It's just safer that way.

I mostly used some old sponge pieces to hold my boards because I don't have a proper clamp setup yet. I'm a bit worried about the permanent stain, since I keep doing this on a wooden workbench surface instead of a PCB. My main concern is if any of those pliable substances will seep into the wood grain and cause actual damage or just a discoloration that I can't clean out later. I think the worry is more about the structural integrity of the holder over time, but I don't really know anything about that. Has anyone noticed any strange reactions between these types of fillers and the wood?

Update: ended up trying the C-clamp idea from earlier and it actually works way better than I expected. Clamping the board edge to the desk keeps it rock solid, so the dough is back in the craft drawer. Also started keeping clay away from component sides after reading about that greasy ring, just in case. The tape-wrapped putty trick sounds handy for odd shapes though.