Dr. Crumley's MAGIC GOO

DR CRUMLEY’S MAGIC GOO
Liquid screws and Instant gasket maker

Dr Crumley’s MAGIC GOO is a product that Joe Crumley introduced to us at his Craftsman’s Workshop this summer.

I've been using Dr Crumley’s Magic GOO quite a bit lately with good results. I started out using it to attach small or warped pieces of material to flat scrap boards that I then sucked down with the vacuum system.

The other day I had an 8' cedar slab sign board that had a bow in it of about 1/2". Vac wouldn't pull it down which was going to cause problems with vcarving if I didn't get it flat. I put it directly on my vacuum bleeder board with a weight on one end and went around that end with the Magic GOO. Waited about 20 minutes and then turned on vacuum under the GOO'd end and moved the weight to other end and GOO'd it and all around the blank. After 20 minutes I turned on vacuum on entire area under blank and it was held down nice and flat - vcarving went great.

Since then I've been using it directly on the spoilboard as an instant gasket whenever a board is not quite flat enough or large enough to hold via just vacuum - it provides plenty of holddown itself, but also provides an airtight seal that makes the vacuum work well. It leaves an orange stain, but does not penetrate deep into spoilboard, so I just clean it off with scrapper until the spoilboard needs resurfacing due to normal cuts into the spoilboard. When I surface the table the residue is shallow enough in the trupan there is no sign of it after resurfacing.

If a board or part being cut is prefinished with something like helmsman or sikkens, a little denatured alcohol on a rag makes removing the orange stain pretty easy. If board is unfinished, the orange stain does not penetrate very deeply, so just a little sanding removes it if it's on a final edge and not on scrap material. Alcohol seems to soften the GOO but does not dissolve it completely if you place a little in a cup of alcohol. The packaging says acetone will remove the uncured foam, so it might work better than alcohol, but I've not tried it. There is a Magic GOO cleaner available from the manufacturer also for use cleaning the applicator gun which I’ve not tried.







The Secret behind Dr Crumley’s Magic GOO?

Don't tell Dr Crumley where you heard it and I'll let you in on it. -- It's Great Stuff Pro Series Gaps and Cracks filler (comes in red can). You have to buy a dispensing gun (there are 3 models that range from about $30 to $60) and a 20oz can of the crack filler is $10 to $12. I'm still on my first can, so not sure how far one can will go, but it lasts quite a while. Most DIY stores do carry small single use cans that don't need a dispensing gun which would be good for giving the product a try.

Magic GOO Info From a web page:

Great stuff Pro Gaps and Cracks is a polyurethane foam sealant. Great Stuff Pro Gaps and Crack filler is closed-cell foam. It forms a water-resistant outer skin when cured. Great Stuff Pro expands to thoroughly fill all voids and cavities making it an ideal air-sealant.

Forms a durable, airtight and water-resistant bond * Bonds to wood, drywall, metal, masonry, glass and most plastics * Tack free in six minutes. Trims in 30 minutes * Wide temperature operating range (25°F to 120°F) Most foams only work in 60°F – 90°F. Freeze/thaw stable * Foam elasticity allows for movement/shifting within a structure from winter to summer * Paintable and sandable.




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Ken,
Would you say that this stuff is strong enough to hold the material down itself or best used only as gasketing material to be used in conjunction with your vacumn?

In your second picture it looks as though the Goo is being used as a gap sealer and adhesive to hold your carving onto a seperate piece of mdf that is being held by your vacumn, is that correct?
Is this something you can find at Lowes?

Jack,

You're correct about the second picture. The part is glued to the board with the GOO and then the board held down by vacuum.

It's a good holdown in itself. Seems to be about the right strength - strong enough to hold something down, yet fairly easy to remove.

I know you can get the small single use cans at lowes, problem with them is once you use a little, the straw clogs up and you basically have to throw away the can. They're really one use only. But would be a good way for you to test for yourself before spending the money for a gun for the pro version.

I bought mine at a more traditional lumberyard near Joes shop in Norman, but expect some of the big box retailers also have the pro version with gun. You can also find it at widely varying prices with an internet search.

Can you possibly post a closer picture of the label? I bought some of this and it looks more like the white foam that expands and gets hard like styrofoam and the can looks just like that one.

Jack did you get the Water based stuff? It comes in a blue can and looks more like styrofoam.

No I got the red can like in the picture, however i did see the blue cans right next to them. I can go get that. Is that the one that looks orangeish in color like above?

Jack here's another picture, hope it's clear enough with the reduced size needed to post.

It's made by DOW and is called Great Stuff Pro Gaps and Cracks - you want the one that says Gaps and Cracks as there are other kinds. UPC code is 041343005833 for the 20oz pro size.

I have only used the pro series - I only assume that the stuff in the small can at Lowes is the same - could possibly not be.


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Jack,
Did a little looking around on Dow Great Stuff site: http://greatstuff.dow.com/

Looks like the DIY gaps and Cracks and the Pro version are likely different as the properties listed are somewhat different:

DIY version: http://building.dow.com/na/en/produc...gapscracks.htm

Pro version: http://building.dow.com/na/en/produc...gapscracks.htm

SO, know the Pro series works, but the DIY cans appear to be different and I have not tried them at all! Looks like need to stick with the PRO series.

Ken and everyone,

When I introduced Great Stuff on the forum, I was using it as a temporary hold down where a vacuum wasn't appropriate. Now since Ken's has played around with it he's discovered even more uses. One of which is it's non-pourus. It dries fast and since it's a chemical version of HDU there's considerable resistance to paint thinners.

Presently, I'm building a 5'X6'X8" ground sign. The depth comes by the use of 2" EPS foam. I used a thin coat of Great Stuff as the adhesive to combine the panels. This stuff is deceptive as glue. It's not as strong as Gorilla Glue but from the same family and chemical resistant.

Thanks again Ken for your informative post. I'll give it a try as a sealer.

Joe

I just did a careful examination of the can I have and it does NOT say PRO on it. So that must be the issue. I will check the links above. thanks