How to get that lumpy finish?

[cooljw]

When epoxying an otherwise flat and smooth concrete garage floor, how do you get that really lumpy bumpy finish? Here is an example:

Is it just a matter of doing a number of coats with lots of paint flakes on each coat? How many coats? How much paint flakes?

When I epoxied my garage floor I sprinkled paint flakes on the last coat and the end result was a smooth finish with some paint flakes on top, like this:

I may be doing another garage and would love to get the lumpy finish by myself.

 

[PAToyota]

A lot of it depends on the product used. Hard to say, but the first picture looks like it may be a troweled on epoxy finish.

 

[boiler7904]

You cover the entire floor with flakes to the point of rejection. Rejection is where the flakes are no longer able to adhere to the wet epoxy film surface. Once it dries completely, you sweep / vacuum the excess flakes off and then clear coat.

 

[thegarageguy]

thats called a "full broadcast". The difference is that you probably used 10 lbs of flakes for 400 sqft as apposed to 100 lbs of flakes for 400 sqft. With this type of floor you would need to seal it with clear epoxy then polyurethane it or just top coat it with polyurea. You cannot just polyurethane a full broadcast floor. polyurethane is meant to go on thin and does not seal the chips properly and when laid on too thick could become brittle and fail. At least this has been my experience.

 

[cooljw]

I worry that using so many paint chips to the point of rejection will cause a fairly weak bond with the chips and the epoxy. So even if you top coat with clear epoxy, the chips could still come off the layer of epoxy underneath and cause the entire finish to fail. Is that a valid concern, does that happen?

 

[Fuller]

I worry that using so many paint chips to the point of rejection will cause a fairly weak bond with the chips and the epoxy. So even if you top coat with clear epoxy, the chips could still come off the layer of epoxy underneath and cause the entire finish to fail. Is that a valid concern, does that happen?

The chips are PVA (plastic). The epoxy will wet them from the bottom up. Try to get a uniform thickness of epoxy (cross roll) before you start throwing chips. By throwing to rejection you assure a consistent thickness and texture to your finished product. Don't worry about those chips being bonded. Yeah, the partially adhered ones will scrape off but the fully saturated ones are stuck tight. A second coat of clear epoxy fills in the texture and a urethane coat is nice for a final finish coat. Pay attention to your recoat windows.

I typically use about 10 pounds of chips per 100 sq ft to fully saturate a chip floor. (100 lbs for 400 sq ft sounds like a typo - or massive overkill).

 

[WolverineCoatings]

PVA is Polyvinyl Acetate... We (all of us) use it because it's cheap and it 'flakes' easily... It's a fairly weak resin and is used in things like white glues (like elmers or cheap wood glue)... Most decent epoxies are going to wet those flake out just fine if you are broadcasting into it.

Boiler and Fuller have it dead on... It is a good idea for novices to broadcast the first layer of flakes into a colored basecoat just in case they do not actually get the 'full coverage' they desire. If you miss a little spot the color will show through. Of course, it adds an extra step. The other keys have already been mentioned... For the look you posted in the pic... broadcast the flakes into an even coat of clear until rejection. Let it harden, sweep/light scrape, and then clear it to seal it. Some people do a couple of layers of chips as well. Last, you can use a product like our SuperGrip 102 in the clear to add anti-slip properties. The SuperGrip 102 is a clear particle that adds traction. You can probably find something local cheaper than the shipping. It doesn't take much...

 

[Hammerdown]

To get that look and texture I would recommend using the flakes in this manner- on the color coat broadcast the flakes until ablout 50% of the floor is covered. This leaves enough of the epoxy exposed so that the clear coat will be able to form a good bond. When it is dry apply the clear coat and broadcast the remaining 50% coverage of the flakes onto it. Let it dry. Then apply another clear coat over the entire area. This should create the look and texture you want, while also ensuring that each coat is bonded to the previous one.

 

[Dave88LX]

Regarding the anti-slip additive, does it make the floor feel abrasive like sandpaper? Shred mops and rags? Or does it just give it a little grip...

 

[thegarageguy]

To get that look and texture I would recommend using the flakes in this manner- on the color coat broadcast the flakes until ablout 50% of the floor is covered. This leaves enough of the epoxy exposed so that the clear coat will be able to form a good bond. When it is dry apply the clear coat and broadcast the remaining 50% coverage of the flakes onto it. Let it dry. Then apply another clear coat over the entire area. This should create the look and texture you want, while also ensuring that each coat is bonded to the previous one.

Then this would not be what he's looking for. He wants a full broadcast floor. Your concerns of "good bonding" aren't justified. Full broadcast floors with no base coat showing have been done successfully without failures for years and years.