made a real mess! - Page 1
Forum section: electronics / general

author: jmelson
author_rank: Super Contributor
timestamp: November 01, 2017, 05:19:13 pm
content: My homebrew reflow oven is a GE toaster oven with a thermocouple temp controller with ramp and soak capability. To get accurate temp control of the PCB, I poke the tiny thermocouple into a plated through hole in the board. I've done well over a thousand boards this way with great results.Well, yesterday, for the first time, I FORGOT to put the thermocouple into the PCB. I started the process and walked away. When I came back, the shop was full of smoke, and the boards were seriously burned. I put the boards into a sealed container, and cleaned the inside of the oven with solvent, but the place still STINKS! It is the smell of burned epoxy. There were big globs of black goo on the bottom of the oven, I scraped them off and discarded them. But, it is stinking up the whole house. Anybody have any ideas how to get rid of this?Thanks,Jon

author: Royce
author_rank: Contributor
timestamp: November 01, 2017, 05:46:11 pm
content: Ozone generator?

author: Kjelt
author_rank: Super Contributor
timestamp: November 01, 2017, 07:24:33 pm
content: Oven cleaner spray, the one with the most warnings on the can.

author: Mattylad
author_rank: Regular Contributor
timestamp: November 01, 2017, 07:48:24 pm
content: A dog, take it out, let it play in puddles - bring it home.Repeat for a week.The smell will soon change

author: jmelson
author_rank: Super Contributor
timestamp: November 01, 2017, 08:06:22 pm
content: Quote from: Kjelt on November 01, 2017, 07:24:33 pmActually, the oven looks REMARKABLY clean, for having a FIRE going inside it for a minute! I did clean it a bit, but the smell does NOT seem to be coming from there. I think the smoke was absorbed by the walls and ceiling wood material, and I don't know how to get it out of that. I am ventilating the place when I'm there. Hopefully, it will dissipate soon.Thanks,Jon

author: Cerebus
author_rank: Super Contributor
timestamp: November 01, 2017, 08:12:36 pm
content: Quote from: Kjelt on November 01, 2017, 07:24:33 pmIs that the one Wile E Coyote uses? "ACME Dynamite Oven Cleaner - use once and you'll never have a dirty oven again".

author: Cerebus
author_rank: Super Contributor
timestamp: November 01, 2017, 08:18:37 pm
content: Quote from: jmelson on November 01, 2017, 08:06:22 pmI did something very similar to you, except it was deliberate. I ran the toaster oven with a bit of FR4 and a thermocouple to deliberately test the limits of the oven and the FR4 gave out after a couple of cycles. I was there, so I probably stopped it earlier in the smoking stage than you did but it was about 10 days before I could walk into the room and not catch a whiff of smoked FR4. This was in summer, so I had the option of having the windows open all day, each day for that 10 days.

author: Mjolinor
author_rank: Frequent Contributor
timestamp: November 01, 2017, 08:38:19 pm
content: Quote from: Mattylad on November 01, 2017, 07:48:24 pmOr for quicker result just feed it some curry.I suggest you may prefer the "before" to the " after" but for sure the before smell will be forgotten very quickly.

author: jmelson
author_rank: Super Contributor
timestamp: November 01, 2017, 09:31:20 pm
content: Quote from: Cerebus on November 01, 2017, 08:18:37 pmWhen I first set up the toaster oven, I just put the thermocouple NEAR the PC board, and immediately saw that the board was overheating. I stopped the temperature ramp before things got out of hand, but the boards did blister a little and turn almost black. That's when I hit on the idea of poking the thermocouple into a plated through hole. Been doing that since 2007.This time, it got WAY out of hand. Looking at the debris, I'd say the boards were probably in flames for a minute or so. Glad these were FR-4, or I would have needed a new oven!Since it is now November, we can't have the windows open too much, although we did do that last night. The house is not too bad, although the smell is detectable in certain rooms. The basement SHOP room, however, is still QUITE stinky. I ran the exhaust fan in my paint booth for a couple hours this morning, didn't seem to accomplish much. I'll have to keep doing this for a while. Maybe when I next use the reflow oven, it will cook out some materials that condensed inside the oven and be worse for a while and then get better. We will see...Thanks,Jon

author: Cerebus
author_rank: Super Contributor
timestamp: November 01, 2017, 09:58:12 pm
content: Quote from: jmelson on November 01, 2017, 09:31:20 pmPerhaps it'd be a good idea to stick it outside on an extension lead and run the oven at 100-150 C for a hour or two to deliberately out-gas any remaining stank before you next actually use it.

author: Mr. Scram
author_rank: Super Contributor
timestamp: November 01, 2017, 10:12:11 pm
content: Quote from: Cerebus on November 01, 2017, 09:58:12 pmJust be sure the neighbour's cat doesn't get stuck in it

author: Cerebus
author_rank: Super Contributor
timestamp: November 01, 2017, 11:58:53 pm
content: Quote from: Mr. Scram on November 01, 2017, 10:12:11 pmI know one or two people on here (You know who you are, TEA addicts) who would regard that as a feature. I can't say I agree with them however.On a more serious note, it might be an idea if you do do this to warn the neighbours that the burning smell is expected, will be gone soon, and isn't cause to call the Fire Brigade.

author: SMdude
author_rank: Frequent Contributor
timestamp: November 02, 2017, 01:53:30 am
content: Perhaps try some bi-carb soda and a fan to circulate the air over it?I bet you're popular with the mrs!!

author: IconicPCB
author_rank: Super Contributor
timestamp: November 02, 2017, 04:32:43 am
content: to get rid of the smell instantly....get a new one

author: MicroBlocks
author_rank: Contributor
timestamp: November 02, 2017, 04:46:20 am
content: Use a filter with activated carbon. It will absorb the smell.

author: casinada
author_rank: Frequent Contributor
timestamp: November 02, 2017, 05:15:36 am
content: http://homeguides.sfgate.com/remove-fire-smoke-smell-apartment-8328.htmlThere are companies that specialize on cleaning up after fires or water damage.It is not cheap as in general they are handled by insurance companies. Good luck with the cleaning.

author: Yellofriend
author_rank: Regular Contributor
timestamp: November 02, 2017, 05:38:13 am
content: I did a max heat test in my toaster oven with a thermocouple fixed on a PCB. The oven can handle well over 300°C - the PCB not. The smell lasted for about one week.

author: DTJ
author_rank: Super Contributor
timestamp: November 02, 2017, 06:44:12 am
content: Maybe for the next lot of boards you should permanently mount a small pcb with a suitable thermocouple hole in the oven.I'm guess in this would work.

author: Kjelt
author_rank: Super Contributor
timestamp: November 02, 2017, 06:59:10 am
content: Quote from: jmelson on November 01, 2017, 08:06:22 pmOk I misunderstood you.That is going to take time.What I would do is camouflage it with airfreshner spray with a more likable smell to taste blue ocean or forest. And buy an airpurifier with indeed an active carbon filter as MicroBlocks already mentioned.Good luck.

author: Smallsmt
author_rank: Frequent Contributor
timestamp: November 02, 2017, 09:24:16 am
content: I had similar problem last year and usedhttps://www.febreze.com/en-usIt worked for me.But need to clean all surfaces first.

author: jmelson
author_rank: Super Contributor
timestamp: November 02, 2017, 05:13:25 pm
content: Quote from: Yellofriend on November 02, 2017, 05:38:13 amAHH! REAL DATA! That's what I wanted to hear. Well, rather than calling Catco or similar fire restoration services, I think we are going to just wait it out, then. I really expected that the smell would eventually fade, after whatever aromatics eventually disperse.My wife throws a fit whenever anyone brings anything smelly into the house (either bad or good odor.) So, she has been remarkably tolerant of this episode, it was PRETTY strong the first night.Thanks yellofriend for the data point!Jon

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 02, 2017, 08:03:30 pm
content: Yup, adsorbed onto the walls most likely. You could try to wash everything with solvent (walls, tables, curtains and chairs, assorted materials laying around), and still not get everything it's touched.Chemically speaking, epoxy volatiles are heavy and resinous, so they evaporate quite slowly. A half-life of a week seems pretty reasonable.If you can tolerate the furnace cranked up to 40C or more, you might be able to bake it out of the house that way -- but as you've only increased the temperature by 10 or 20 degrees, the evaporation rate will only be a few days shorter, probably not worth it. :\Tim

author: jmelson
author_rank: Super Contributor
timestamp: November 10, 2017, 08:40:04 pm
content: Just a little update. I cans till detect a whiff of the smell right near the oven, but otherwise it is gone, thank goodness! I sure hope it will be a long time before I do something that bad again!Jon

author: Cerebus
author_rank: Super Contributor
timestamp: November 10, 2017, 08:44:15 pm
content: So 10 days to the day, which tallies nicely with my experience above where I said that after 10 days I could just detect a whiff.

author: jmelson
author_rank: Super Contributor
timestamp: November 10, 2017, 08:55:37 pm
content: Quote from: Cerebus on November 10, 2017, 08:44:15 pmYup! Actually, it has been pretty faint for a few days, but I've been working on other stuff and didn't spend a lot of time in that area recently. Still, I burned up $200 in parts and bare boards, so I'm not real happy about the incident. At least I didn't burn the house down!Jon