3D Resin Prints Destroyed by Water?

[tehachapifan]

Purchased some 3D resin printed N scale passenger car kits and completed prepping and painting 2 of them with no issues over the past couple weeks. However, the third one completely lost its shape and structure after prepping today. This prep consisted of first using some hot water from the tap to help straighten some minor warping on the bottom edge of the car shell (as I did with the other shells). I did this by either running hot tap water over the area for a few seconds or by dipping the shell in a container of hot tap water for a few seconds only, then apply pressure to reshape. This process seemed to go fine and then, within an hour or so, I washed the shell by dipping briefly in a container of room temp tap water and a drop of Dawn and then rinsing with the room temp tap. The shell looked fine during this process and then I set it aside on the counter to dry. Came back after an hour or so and the shell was a total loss. It looked like it was exposed to heat from a fire. The sides of the shell curled and bowed severely outward at the bottom and the roof bowed into a pronounced swayback. I was unable to correct this deformation and, when I contacted the printer about it, he said that water will indeed destroy these prints by basically un-curing them. However, I can't find any info online cautioning against exposing resin prints to water at all. In fact, I see lots of info recommending that resin prints be cured WHILE submerged in water, plus lots of info about using hot water to straighten parts like I was doing. Has anyone had this happen or heard of it happening? Could it be the relatively thin walls, etc., that exacerbated the issue?

[Chris333]

I have read all sorts of stuff about water and prints. Some say you need to cure prints while they are submerged in water. Some say water will make the parts grow so don't even use water based paints. I dunno who to believe.

I have un warped parts with hot water and then blasted them with cold water to set it. No problems.

[JeffB]

I have un warped parts with hot water and then blasted them with cold water to set it. No problems.

Same...  Though lately I've been using a heat gun to do the heating part of it.

Jeff

[draskouasshat]

Purchased some 3D resin printed N scale passenger car kits and completed prepping and painting 2 of them with no issues over the past couple weeks. However, the third one completely lost its shape and structure after prepping today. This prep consisted of first using some hot water from the tap to help straighten some minor warping on the bottom edge of the car shell (as I did with the other shells). I did this by either running hot tap water over the area for a few seconds or by dipping the shell in a container of hot tap water for a few seconds only, then apply pressure to reshape. This process seemed to go fine and then, within an hour or so, I washed the shell by dipping briefly in a container of room temp tap water and a drop of Dawn and then rinsing with the room temp tap. The shell looked fine during this process and then I set it aside on the counter to dry. Came back after an hour or so and the shell was a total loss. It looked like it was exposed to heat from a fire. The sides of the shell curled and bowed severely outward at the bottom and the roof bowed into a pronounced swayback. I was unable to correct this deformation and, when I contacted the printer about it, he said that water will indeed destroy these prints by basically un-curing them. However, I can't find any info online cautioning against exposing resin prints to water at all. In fact, I see lots of info recommending that resin prints be cured WHILE submerged in water, plus lots of info about using hot water to straighten parts like I was doing. Has anyone had this happen or heard of it happening? Could it be the relatively thin walls, etc., that exacerbated the issue?

mind showing some pictures of the cars?

[bbussey]

That sounds like water-washable resin that wasn’t UV cured. I would complain to the seller.

[John]

That sounds like water-washable resin that wasn’t UV cured. I would complain to the seller.

this!

[tehachapifan]

He says he uses a UV machine and I 've been setting these in the sun for a bit when I first receive them. I did receive one that seemed a bit under-cured, but this one seemed fine.

It looks like I may have actually saved the shell by using a hairdryer and by strategically clamping rigid brass bars along the sides to achieve and maintain shape and straightness (that and lots of tape along the bottom edge to hold it against the underframe). I left the clamped bars on for hours at a time. Is it back to original condition? Not quite. But it appears passable as of right now. Using these bars and clamps along the sides near the roofline also allowed me to remove the swayback sag of the roof, as the wall squeeze pushed up the sag in the roof (the window area had bowed/mushroomed outward and this corresponded with the roof sag). Time will tell if this for sure works in the long term, as I figure there will be some rebound, but it still looks good this AM (although it's still all taped up at the bottom).

[Erock482]

I have heard of some resins that can absorb water, but I think the suspicion of the car sides not being fully cured may be the most likely culprit.