Weld-On 4 manufacturer's website (not intuitive or easy to find)

I cannot find info about Weld-On 4. I need to do some research before I use it.
Does it have another name? I can find it for sale a few places like Amazon, but I can’t find it on the Weld-On website. ugh!

Here is the SDS:


Ironically i was just using it when i saw this post :rofl:. Label says Weld On 4

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I’m so confused. :rofl: Why isn’t it on the Weld-on website?

Thank you!!

Ahhh @beerfaced Thank you, with this, I also figured out where this is on their site. It’s not intuitive though!
They have a separate site for sign and display assembly adhesives. LOL
But it isn’t very searchable when using the name of it. :rofl:

Anyway, mystery solved. I needed to have a definite answer for something today, so thank you. :smiley: My brain feels better. :smiley: (just one of those days LOL)


I stumbled across the SDS on a completely different website. Some plastics site.

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I just spoke to them, a very nice lady.

That is the site as posted above. It’s not listed on what you would think is the official site. Direct link to the product is here, and the SDS is on that page:

Also, it is NOT EPA approved for home, school, personal, use. It’s highly toxic stuff…

The sellers on Amazon/eBay should have warnings about that.

Finally, the effective shelf life is not very long.


Yeah - 2 years.

This is also something I was hoping to find on their site, which was one of the reasons I wanted to find the actual site LOL

What all works and comparing them in various aspects (including reactions, since I’m severely allergic to epoxy).

Just because weld-on 4 is what’s best for the job, that doesn’t mean it’s possible for me to use it. (I reacted to epoxy even with plenty of PPE.) I like using the best products but I also like being healthy. :rofl: @eflyguy yeah - I knew it was bad! ugh… Thanks for looking into that more!

Need to spend some time digging in with this. :slight_smile: And, if nothing really provides what I need, then I’ll just have to be creative and find other ways to do what I need without exposing myself to things that may be dangerous to me. (Maybe stand offs or some other type of connecters, or something along those lines instead of gluing transparent acrylic together)

Thanks everybody!

It’s good stuff, and I have >95% of the small tin I bought probably 4 years ago.

I use tiny dropper/dispensers with syringe-style needles when I need it. Then clean them out with some isopropyl.

It smells ok to me, but I don’t sniff it intentionally! I just suck up a little from the tin, which I only made a tiny hole in to get at it.

I also have a tube of the gel stuff, somewhere. Had that for many years before I got the GF.

Edit - ha! I bought my Weld-on 4 on Feb 4 2018. https://www.amazon.com/gp/product/B00TCUJ7A8


I don’t even have to touch things to react to it though, if the molecules are in the air, I’ve gotten a reaction so bad that I had to use the strongest steroid ointment possible to prescribe for a over a month, after oral meds failed.

It seems to be with chemicals kinda like this that are the biggest issue for me. I know I’d use it outside, obviously, but if I can find something else that is less toxic, then i’d prefer to give that a try first.

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You won’t find anything as effective. The bond it creates is as strong as the material itself. It simply dissolves the surface of acrylic and as it vents off, they become one.

… but it is noxious, for sure.

Other adhesives just “stick” to each surface, but can never be as strong.

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Ok, thanks… I will be doing my research based on their site to see what I’ll do.

It is very difficult to use as it is extremely runny and evaporates just short of a full boil at room temps. I keep it in the freezer in the can in a glass jar with a metal lid. When it works it makes two pieces just one piece, but one drop not wanted will leave a mark.

If the temps are the same in C and F outside that might be a good time to use it outdoors.

I have one of these. I also have almost every other cordless tool Ryobi makes. I’m not a fan-boy, I just made a choice to choose one product line over a decade ago due to buying and maintaining batteries for so many tools.

I has come in really handy dozens, if not hundreds of times. Air circulation wherever you need it. It can also run on AC (has a plug, which mates to any extension cord, next to the battery connection.)

So even though I’m not particularly sensitive to fumes, just getting a little air moving over stuff I’m applying some kind of finish to, helps.

I think you won’t even want to get near Weld-On 4 then. In Southern California we can’t get it shipped in, it’s banned by the AQMD unless you’re a large business. We can get Weld-On 4SC, maybe that one would work for you?

That’s like offering this guy a bandaid!
:rofl: :rofl: :rofl:

@ekla You’re pickin’ up what I’m throwin’ down. :smiley:
Yeah, exactly - I’m gonna research the other ones that are in that chart for acrylic to acrylic. :slight_smile:


Are you sure you’re allergic to all epoxies? Hardman epoxies don’t contain any harsh solvents. I use Epoweld 8200. It works great for me. Double/Bubble Blue is Epoweld 8200 in a one-shot pack

For what I was using epoxy for, I needed a two-part epoxy. I do have another product that I can use now (Crystalac, which is nontoxic). It’s great, but can’t be used for pouring into molds. I don’t think there is an epoxy that I’d be able to use safely for pouring into molds.

But after something like 3.5 months, 3 dr appts with two diff doctors, and 3 prescription meds, I’m all good. :smiley:

Someone forgot to tell amazon that :rofl::rofl: after being recommended to it by someone at a maker space in costa mesa, I’ve bought it from amazon twice. The last can was recently… because i lent out the first unopened one i bought and it was never returned.

I think it’s the #4. This is the one i purchased

Weldon #4 with Applicator Bottle - 1/4 Pint - 4oz - 10308 - 1 each https://www.amazon.com/dp/B00TCUJ7A8/ref=cm_sw_r_apan_glt_i_XFEXMEY6HA8VMYZ7GD78?_encoding=UTF8&psc=1

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Nah, Amazon knows. In the fine print of that listing:

“ This product may not be shipped into Los Angeles, San Bernardino, Orange, or Riverside Counties. Plastic-Craft Products reserves the right to substitute Weld-On 4SC for Weld-On 3 or Weld-On 4 when ordered for delivery to zip codes in those counties.”

I’ve only been able to pick up regular Weld-On 4 in Los Angeles in person from a plastics supplier, even then they check for a business license before selling to you.