Food Dehydrator for paint drying

Greg

Just a heads-up, not sure you should ever expect a rock-hard finish with Vallejo, even with a dehydrator.

Appreciate the words of caution.

I like the results I get with Vallejo paint but the durability has been it's achilles heel  Even a slight increase in durability will be a win. 

I've mixed the snot out of this stuff and put it on nice and thin and still had it peel right off.  I won't itemize the lengths I go through to help improve adhesion and durability, but it can be a pain.

I'll probabaly try something like what Don did and cobble something together with a lightbulb as a heater for testing. 

PhoenixG

I'll probabaly try something like what Don did and cobble something together with a lightbulb as a heater for testing.

Great idea.

PhoenixG

I've mixed the snot out of this stuff and put it on nice and thin and still had it peel right off.

You probably know this, but although I think Vallejo adheres pretty well (for an acrylic, that is .......if allowed to cure), I always use a good primer under it. Tamiya, Stynylrez, Mr Surfacer, etc. I've never had great luck with Vallejo surface primer.

I still use Vallejo because it self-levels like no other acrylic I've used, and the good color selection. (not to mention that I went goofy buying the stuff back in '13 when I got back into the hobby).

Hope you let us know how the dehydrator/dryer experiments work out.

Greg

 

 

PhoenixG

Thank you Greg for asking this question!

 

You're welcome.

Just a heads-up, not sure you should ever expect a rock-hard finish with Vallejo, even with a dehydrator. But perhaps. I'm starting to question myself if I've been failing to mix thoroughly and I think I already said I have tended to lay it down way too thick. Neither would lead to a nice hard finish.

11 yrs later and I'm still testing. Never said I was the fastest learner.

 

Hah ! I NEVER STOP TESTING as it's a hobby in itself for me, seriously !

But a casual observation much as your own, say I spray a plastic canvas roof with Stynylrez and top coat with MA, then dehydrate ( I have done this). That roof is then likely to sit a week before I get back to this piece. But I notice it feels truly cured, it's really dry. That just confirms what you already stated in another post. I just do fingernail scatch tests personally and never would do that straight out of the dehydrator but rather after cooling and probably the next day. Vallejo MA passes a solid moderate scratching at that point. Within a few days it just feels all the more dry and hard shell. This beats what you have said about room temp air drying by quite a margin. And I've only ever shot Vallejo over Stynylrez ( also dehydrated but only 30 minutes) so I can't speak for it's ability to stick to bare plastic at all.

I'm an advocate of dehydrators or those paint dryer cabinets,some of which are not priced bad at all imo.. Even the home made one mentioned within this thread ( if they employ moving air with something like a computer fan just to keep the air fresh and some form of temp control). Even to lift the box an inch and use a box fan to pass air by the dehydrator might be sufficien to change air supply inside the box continually.

By the way, I believe craft paints benefit from similar treatment. I've found them to be quite hard shelled and durable in my tests when heat set in the dehydrator. I have no qualms about using craft paints in my builds as long as things are primed and I dehydrate them. The same can be said for Goldens High flow artist paints and Liquitex Soft Body, even Liquitex Basics line acrylic artist paints can be thinned and airbrushed. These all airbrush great when mixed right.Golden High Flow and Liquitex Soft are both rated for either brush or airbrushing anyway. They even make an airbrush medium for them, though that tends to addsheen to the paints so I don't always use it.. Nuff said today lol.

oldermodelguy

Hah ! I NEVER STOP TESTING as it's a hobby in itself for me, seriously !

Interesting you mention that. As I've been messing with paints and techniques and the new dehydrator and lots of plastic spoons the past couple weeks, it occurred to me that I think I enjoy fiddling and testing as much, if not maybe more, than building.

I must say that even that process is more fun with the dehydrator, because of getting to see results faster. I've even taken a liking to square bottle Testors enamel again.

Thanks for your thoughts, always interesting.

I found another modeling use for my paint dryer.  I created a base and modelled some ground cover using celluclay.  I make it fairly wet, so it dries slow.  Putting it in my paint dryer sure speeds things up!

missileman2000

I found another modeling use for my paint dryer.  I created a base and modelled some ground cover using celluclay.  I make it fairly wet, so it dries slow.  Putting it in my paint dryer sure speeds things up!

 

 

That's a great tip, Don.

Which reminds, keep forgetting to ask. Will a dryer/dehydrator speed up regular plastic cement drying time? I would think no, since the joins are internal (well, mostly)

Greg

Which reminds, keep forgetting to ask. Will a dryer/dehydrator speed up regular plastic cement drying time? I would think no, since the joins are internal (well, mostly)

Seems like it might shorten the time a little bit.  I would think the higher temperature would accelerate the evaporation of the solvents.  Whether that would be a good thing or a bad thing, however, is another story.  It might serve to weaken a cement weld by not giving it enough time to work.

Greg

 

 

oldermodelguy

Hah ! I NEVER STOP TESTING as it's a hobby in itself for me, seriously !

 

 

Interesting you mention that. As I've been messing with paints and techniques and the new dehydrator and lots of plastic spoons the past couple weeks, it occurred to me that I think I enjoy fiddling and testing as much, if not maybe more, than building.

I must say that even that process is more fun with the dehydrator, because of getting to see results faster. I've even taken a liking to square bottle Testors enamel again.

Thanks for your thoughts, always interesting.

 

Yes. I've been decanting and mixing colors in mostly solid pastels and such with the intent of using those in future classic car builds. Namely Rustoleum Painters Touch and 2x spray paints. It's 12oz of paint per can almost ready to airbrush for basically $5. I'm gaing a small collection of these enamels. I add a bit more lacquer thinner and they spray every bit as nice as the little Testors bottles or the old MM enamels. I shoot them through the Paasche H with #3 tip. Great gloss and smoothness for old cars, pretty much a ready to build finish with slight buffing once cured. Well, to my eye anyway.

Eaglecash867

 

 

Greg

Which reminds, keep forgetting to ask. Will a dryer/dehydrator speed up regular plastic cement drying time? I would think no, since the joins are internal (well, mostly)

 

 

Seems like it might shorten the time a little bit.  I would think the higher temperature would accelerate the evaporation of the solvents.  Whether that would be a good thing or a bad thing, however, is another story.  It might serve to weaken a cement weld by not giving it enough time to work.

 

That's a good point.

By the way this is the airfryer dehydrator I use, dry paint by day cook pizza by night, bake scallops for Sunday dinner lol. $165 at Amazon right now:

oldermodelguy

By the way this is the airfryer dehydrator I use, dry paint by day cook pizza by night, bake scallops for Sunday dinner lol. $165 at Amazon right now:

 

Nice.

Which reminds me what a ditz I am. I'd been hinting at a countertop air fryer for a long time, but my domestic partner has used her veto power. I bought a large dehydrator, similar to yours but it is a dedicated box.

I had since realized I should have gotten a combo unit as you did.

Do you ever worry about putting food in the same space where solvent vapors have been floating around? I've been perusing about this for a couple of weeks now. No big deal, it's just how my mind works...curious.

Eaglecash867

 

 

Greg

Which reminds, keep forgetting to ask. Will a dryer/dehydrator speed up regular plastic cement drying time? I would think no, since the joins are internal (well, mostly)

 

 

Seems like it might shorten the time a little bit.  I would think the higher temperature would accelerate the evaporation of the solvents.  Whether that would be a good thing or a bad thing, however, is another story.  It might serve to weaken a cement weld by not giving it enough time to work.

 

Gee, the main reason I go to liquid (solvent) glues is to slow the drying time

Greg

 

Do you ever worry about putting food in the same space where solvent vapors have been floating around? I've been perusing about this for a couple of weeks now. No big deal, it's just how my mind works...curious.

 

No but you should keep what you have, Greg. Cabinet style is nice.

What bothers me is two part paints, actually scares me they offer them for home hobby use. I all but ate regular enamels in 1/1 but when all the warning bulletins came around on two part catalyzed paints I took them to heart.

oldermodelguy

No but you should keep what you have, Greg. Cabinet style is nice.

No worries, I won't. I got mine downstairs in plain sight without incident. Not interested in pressing my luck.

oldermodelguy

What bothers me is two part paints, actually scares me they offer them for home hobby use. I all but ate regular enamels in 1/1 but when all the warning bulletins came around on two part catalyzed paints I took them to heart.

I recently bought some and honestly wasn't aware of this. Thanks for the heads-up, I will do some reading.

Greg

 

I recently bought some and honestly wasn't aware of this. Thanks for the heads-up, I will do some reading.

 

Don't panic about it and use common sense, use an organic particulate mask good for solvents, latex or whatever gloves, safety glasses or goggles and your booth. You'll be fine. But the isocyanates in the activators can enter through skin and eyes even in the curing process until the paint kicks. Unwary don't realize this and might spray the stuff regularly with just a dust mask and improper venting and those folks are my concern..One shouldn't try to beat or cheat the system in this case. I think your reading will support my claims.

missileman2000

Gee, the main reason I go to liquid (solvent) glues is to slow the drying time

I use them for all styrene to styrene assembly.  Nothing else makes a permanent weld...but...I already covered that.

oldermodelguy

 

 

Greg

 

I recently bought some and honestly wasn't aware of this. Thanks for the heads-up, I will do some reading.

 

 

 

 

Don't panic about it and use common sense, use an organic particulate mask good for solvents, latex or whatever gloves, safety glasses or goggles and your booth. You'll be fine. But the isocyanates in the activators can enter through skin and eyes even in the curing process until the paint kicks. Unwary don't realize this and might spray the stuff regularly with just a dust mask and improper venting and those folks are my concern..One shouldn't try to beat or cheat the system in this case. I think your reading will support my claims.

 

Thanks for the additional info.

I almost regret the purchase. Not sure I need anything that durable, and even though my vent/exhaust system is extremely good, I don't think I need to be using such nasty stuff in the same house as my wife, for medical reasons.

Greg

You probably know this, but although I think Vallejo adheres pretty well (for an acrylic, that is .......if allowed to cure), I always use a good primer under it. Tamiya, Stynylrez, Mr Surfacer, etc. I've never had great luck with Vallejo surface primer.

I've only ever used the Vallejo primer.  And while it can improve adherence I can't say that it's anything great.   My first test will be against the plain primer.

Greg

I still use Vallejo because it self-levels like no other acrylic I've used, and the good color selection. (not to mention that I went goofy buying the stuff back in '13 when I got back into the hobby).

My journey was similar.  Vallejo is what I picked up when I started thinking about resuming the hobby in '19.

Greg

Hope you let us know how the dehydrator/dryer experiments work out.

I just finished cobbling together a ghetto dryer out of a spare cardboard box and parts from an old heat lamp.

It's a 60w bulb in there now.  Let it run for about 4 hours while keeping it under observation.  The socket is ceramic so very little heat transfer from that.  Cardboard is showing no signs of discoloration and it held at 110F about 3" from bottom.   Air flow is going to be ok given it will draw cooler from the bottom and vent the hottest at top where the bulb is.

Ready to paint some parts and give it a whirl!

Drying booth looks good. Let us know how it works out as your tests progress.

Do you have the lightbulb on a dimmer so you can control the temp? (That is Don's (Missileman's) idea, not mine)

I'd be very interesting in hearing your results testing Vallejo Surface Primer against other primers. As I said, aside from the fantastic leveling and detail preservation, I was never able to get it to adhere very well nor sand it. I've always wondered if maybe I got a bad bottle all of those years ago.

PhoenixG

 

 

Greg

You probably know this, but although I think Vallejo adheres pretty well (for an acrylic, that is .......if allowed to cure), I always use a good primer under it. Tamiya, Stynylrez, Mr Surfacer, etc. I've never had great luck with Vallejo surface primer.

 

 

I've only ever used the Vallejo primer.  And while it can improve adherence I can't say that it's anything great.   My first test will be against the plain primer.

 

 

Greg

I still use Vallejo because it self-levels like no other acrylic I've used, and the good color selection. (not to mention that I went goofy buying the stuff back in '13 when I got back into the hobby).

 

 

My journey was similar.  Vallejo is what I picked up when I started thinking about resuming the hobby in '19.

 

 

Greg

Hope you let us know how the dehydrator/dryer experiments work out.

 

 

I just finished cobbling together a ghetto dryer out of a spare cardboard box and parts from an old heat lamp.

It's a 60w bulb in there now.  Let it run for about 4 hours while keeping it under observation.  The socket is ceramic so very little heat transfer from that.  Cardboard is showing no signs of discoloration and it held at 110F about 3" from bottom.   Air flow is going to be ok given it will draw cooler from the bottom and vent the hottest at top where the bulb is.

Ready to paint some parts and give it a whirl!

 

My 60W drying booth also runs at 110.  For a few things I'd like it a little hotter.  Been looking for a 75 W incandescent bulb- hard to find!

OP: I would think 110f would be fine for most things including enamels. If it maintains that temp and has air movement you should do well with it. You will know as you get to using it more.

Don or anyone interested: On another note, Amazon lists incandescent bulbs from 15-500 watts or more.

oldermodelguy

Don or anyone interested: On another note, Amazon lists incandescent bulbs from 15-500 watts or more.

You can also find ceramic heat emitters with a pretty wide range of wattages that screw into an ordinary light socket.  Used those for my reptiles when they were babies.

Eaglecash867

 

 

oldermodelguy

Don or anyone interested: On another note, Amazon lists incandescent bulbs from 15-500 watts or more.

 

 

You can also find ceramic heat emitters with a pretty wide range of wattages that screw into an ordinary light socket.  Used those for my reptiles when they were babies.

 

Great!  Thanks.

It holds 110F very consistently.  If I were to add a shelf to it and get to 8" from bottom the temp rises to120F consistently.

I took a sprue and painted it with primer and cut it in half.  One half went in the Bulb powered dryer and the other half sat out.  I let them cure for a solid 12 hours.

The sprue in the dryer came out with a very smooth dull finish.  The one that dried outside had a tacky feel to it and a slight sheen. 

Running the edge of my thumbnail along the long stem.  It scuffed the dried part but lost no paint.  Same test on the air dried part took chunks out.

Applied the sander to the heat dried part and the primer came off with some effort in a beautiful powder.  That was a first for me! 

The other sanded off as well but left chunky black bits in the sander.

New favorite painting tool is my cobbled together heat box! 

Thank you Greg for starting this thread (even though I didn't use a food dehydrator)!

Greg

Do you have the lightbulb on a dimmer so you can control the temp? (That is Don's (Missileman's) idea, not mine)

There's no dimmer on it.  It's full power on.  I left a couple of small gaps by the handle punch outs at the top.  Ostensibly to promote airflow and allow some of the heat to escape.  Luck was on my side as I hit 110F right off the bat.

Greg

I'd be very interesting in hearing your results testing Vallejo Surface Primer against other primers. As I said, aside from the fantastic leveling and detail preservation, I was never able to get it to adhere very well nor sand it. I've always wondered if maybe I got a bad bottle all of those years ago.

I've had the exact same problems with Vallejo primer as you.  It wasn't the bottle either.  I've used primer from three different colors and bought across different years and whenever I tried to sand it the primer peeled rather than sanded.  The results with the drier were the first time I had been able to successfully sand a part and even get the edges to feather! 

I've started curing all my Space Sub's parts in it since completing this test.  Fingers crossed the results are consistent.

PhoenixG

I've started curing all my Space Sub's parts in it since completing this test.  Fingers crossed the results are consistent.

That's exactly the point we are stressing I think,that by using the heated drying boxes of whatever iteration that results are not just faster and stronger curing of paint, but more consistently so. Congrats on your rig working well for you ! It's exciting whenever we step out in faith and things turn out so well.

PhoenixG

Thank you Greg for starting this thread (even though I didn't use a food dehydrator)!

You're surely welcome. I'm as thrilled as you are with my new machine. I don't put off paint jobs anymore, dreading the drying time. (that makes no sense, I know.....but it's how my ditzy mind sometimes works). I'm glad you were incented to make a drying box....gives me somebody to share my enthusiasm with.

I'm amazed at your report about the Vallejo Surface primer. I've never read of anybody being successful in sanding the stuff. That sure adds credence to OMG's comment directly above (about dehydrator/drying box effecting more than just drying time)

I haven't personally used Vallejo primer but every review points to it being non sanding. And they all air dried the primer and at that I don't believe any gave it 24 hours air dry time as Vallejo themselves say should be the standard for the primer. So indeed that's a surprise to me too that it was sanded smooth as reported here after heat drying.I'll probably still use Mr Primer Surfacer and Stynylrez primer though. I'm familiar with their capabilities and have no reason to look beyond them other than the curiosity factor..

oldermodelguy

It's exciting whenever we step out in faith and things turn out so well.

Seeing the examples others in thes forum taking those leaps has made it easier for me to do so.  Each one has been rewarding in it's own way.  Even the ones that didn't quite turn out

Greg

I'm amazed at your report about the Vallejo Surface primer. I've never read of anybody being successful in sanding the stuff.

I'd caution that it was only a single test and the results with sanding may have been a freak accident.

I have primed several pieces of the model I am currently working on (no sanding) and the durability of the coat is definitely much higher.