FR4 Print Surface. you need to try this stuff

I recently tried a sheet of FR4 as a print surface and its amazing. I have been using PEI for 5yrs and FR4 works better.

FR4 is similar to something called G10/Garolite but FR4 is fire resistant., and its mainly used as PCB circuit Board material. The one I purchased has one side covered in copper. you dont print on the copper side.

FR4 isn’t expensive. I ordered a 12" x 12" sheet from Amazon for $20 shipped
MGChemicals make this stuff and Im hoping 3D printing Canada will start to carry it. as MGChemical is from Burlington.

I ordered from here is link (not affiliate)

Here is a video talking about it.

Actually, the correct designation is “G10” as that describes the fibreglas/epoxy content. “G10-FR4” indicates that the G10 material has fire retardant chemicals added to it. What you’re calling “FR4” is actually “G10-FR4”.

Doing a quick look around the Interwebs I see that “G10” and “FR4” are used interchangeably which can be problematic when choosing material to buy.

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I’m only being pedantic about it because unless you absolutely understand what you want and what you are buying you will get inconsistent results. Using a PCB like you are is very hit and miss because of coatings that may or may not be put on the bare fibreglass side (ie is it easier for them to coat both sides with a UV mask).

MG Chemicals is generally a pretty good company but I find that a lot of their products are sourced with regards to price rather than to specification and that has caused me some problems - their 3D filament is a great example of different spools bought on the same day from the same source having different characteristics and no lot number/sourcing information which has resulted in some models coming out great and others … not so great.

Apparently the thickness of the board matters also.

yes I have their 1.5mm board. it feels ideal. ridged but still a bit of flex.

flatness has been quite good.

Not exactly correct. If you add the flame retardant (bromine) it is not longer g10or g11 for that matter. But FR4 ,6, or 8 (it isnt the same a gf in polyesters that describe the amount of glass to resin) be that as it may Bromines are quite toxic. I am not certain how bound they are in the matrix of epoxy and if heating it will free bromines or bromides but it is a serious serious health issue if it does.

I would suggest using actual G10 and forgoing the flame resistance as bromine gas is lethal if inhaled. It just seems an unnecessary risk to me.

Using a material not the the manor of how it is intended may have effects that are unexpected. Maybe it doesn’t release. But the penality for being wrong is too high.

not exactly burning this stuff in a steel can and inhaling all the fumes lol. warming it up to 65 degrees and printing on it. feels very low risk IMO

Your choice, I work with bromides everyday professionally. It literally is lethal if inhaled even at low concentrations 0.1 PPM. It reacts poorly with alcohols and ammonias among others. It is a HUGE hazard if your guesses are wrong. G10 has a far less potential for mayhem.

Good to know thank you, I will look for some regular G10 just incase.

According to NEMA, the correct designation is “G10 Grade FR4”. Here’s the first 8 pages of the specification, I guess you have to pay for the complete document:

Honestly, I wasn’t aware of the toxicity of adding the bromide, good to know. I did know that inhaling G10 dust was bad for you (don’t want to get glass fibres in your lungs).

I first started working with G10s (other than in PCBs) from different manufacturers in the early 1980s for use in text fixtures and structural applications and I have seen quite a few differences in materials that call themselves “G10s” or “FR4s” or “G10/FR4s” which was my point; just because something you found on the internet from one company at one instant in time works well for you don’t expect a) that other source have products that behave the same way and b) don’t expect the same source will provide you with a product that behaves consistently if they don’t provide you with a good datasheet.

On that last point, I should make a retraction about my blanket statement about MG Chemicals originally - they do have a pretty comprehensive datasheet for their copper clad G10/FR4 materials which means that you should receive a consistent product from them.

Although, I must point out, that I haven’t been happy with the consistency of MG Chemical’s PLA across different spools.

That is interesting. The supplier we buy from lists nema grade FR1-4 (Brominated) and sells nema grade G3,9,10,11 (non-brominated) separately. One is listed with a UL-95 flame resistance and the other is not. Other than this they have the exact same. Either way brominated is listed with a FR4 (or 123) I guess double check the G series for bromine.

I might be an old catalogue too.

I’ve always been told that “FR4” is a G10 variant, not a separate material. To be fair, I’ve heard people refer to PCB material as “FR4” as a kind of shorthand as well as by people who didn’t know the difference.

I only put in the original post because I have a long and frustrating history with G10 as it comes from many different sources with many different physical characteristics that are either lost or ignored by resellers that just present their wares as “G10”.

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clear as mud

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