Is this a cleaner or a primer?

The manufacturer describes it as a cleaner primer, which is why it exists. On an EPDM roof the wash-down and the priming are the same operation: it goes on, is rinsed off and the roof is left to dry. The data sheet states how it is applied and what it is applied over.

What goes on after it?

Under the acrylic system, KST041321, the gray single-ply acrylic base coat, which then has to be topcoated with an acrylic finish coat such as KST041300. Under silicone, nothing but the seam work: open seams and flashings sealed with the black MS hybrid KST058310, then Silicone44 KST044300 (white) or KST044320 (gray) with no base coat.

Does it work on TPO, PVC or Hypalon?

No. The current data sheet makes it an EPDM product, and not for white EPDM. Under the acrylic system, TPO, PVC and Hypalon are pressure washed and go straight to the single-ply base coat KST041321; weathered TPO and PVC take Silicone44 directly after an adhesion test. For sealant work on TPO and PVC there is a separate adhesion promoter, KST058700.

No. It is for weathered EPDM. New membrane that has not weathered takes a different primer under a coating, so tell us the age of the roof and ask us before you order.

No. The manufacturer states 100% water based for this primer. The solvent-based materials in this catalog are called out on their own pages and they ship differently.

Coverage comes from the manufacturer product data sheet and depends on the membrane and its condition. Send the roof area, the membrane type and the site ZIP through the quote form and the quote states the pail count, the delivered price and the ship window.

Base coats & primers

KST038620 Uniflex Bond-It Wash Primer, Clear

Single-ply wash primer
Sold by the pail

Bond-It is the clear wash primer that prepares weathered EPDM for a coating, under the Uniflex acrylic system and under Silicone44 alike. The manufacturer calls it a cleaner primer, and it is for EPDM only: not TPO, PVC or Hypalon, and not white EPDM. Stocked in 5-gallon pails and quoted per project.

Key benefits

Two jobs in one pass: the manufacturer describes it as a cleaner primer for EPDM, so the wash and the prime are the same step
100% water based, which is why it is the step that opens an EPDM restoration rather than a solvent wipe
Used under both routes on EPDM: the single-ply acrylic base coat, or Silicone44 with no base coat at all
Substrate line is specific: EPDM only, and not white EPDM, so TPO, PVC and Hypalon build-ups leave it out
One pack size, the 5-gallon pail, which keeps a large membrane roof simple to count

Priced per project

Send the quantity and the delivery ZIP. We reply within one business day.

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Shipping & returns

Overview

An EPDM restoration starts with a wash, and Bond-It is the Uniflex product that makes the wash do double duty. The manufacturer calls it a cleaner primer: one clear, 100% water-based pass over weathered EPDM that is rinsed off before anything is coated. Its current data sheet makes it an EPDM product only. It is not for white EPDM, and it does not go on TPO, PVC or Hypalon.

It sits under both coating routes on an EPDM roof. Under the acrylic system, KST041321, the gray single-ply acrylic base coat, goes on next and must be topcoated, and a finish coat such as KST041300 closes the system. Under silicone there is no base coat: open seams and flashings are sealed with the black MS hybrid KST058310, and Silicone44 KST044300 (white) or KST044320 (gray) goes straight on. New EPDM that has not weathered takes a different primer under either route, so ask us.

Application

The membrane has to end up clean, dry and sound. Ballast, debris, loose plates and torn seams are prep work, and the primer is not a substitute for any of it.
Repair the details first: open seams, fastener plates, curbs and penetrations are closed before the field is coated.
Prime by substrate. This is the primer for weathered EPDM; TPO, PVC and Hypalon go without it, and a metal or concrete deck takes a different primer or none.
Apply at the rate and in the manner the manufacturer’s product data sheet states, inside its temperature window, rinse it off, and let the roof dry as the sheet requires before the next coat.
On a silicone job, run the adhesion test after the wash: a low result goes to Uniflex, which decides the primer.
Keep the recoat windows between the coats exactly as the sheets state; on a membrane roof that sequence is the system.

Ordering

KST038620 comes in the 5-gallon pail. Stocked material ships in 1 to 3 business days; anything not on the shelf is ordered in and runs 1 to 2 weeks. Pallets of pails, the drums and totes of base coat and finish coat that follow, and the freight for all of it go through the quote form with your part numbers, quantities, site ZIP and dates. Every price here is quoted per project.

Where it's used

Weathered EPDM

Aged black EPDM being restored with a coating instead of replaced, where the membrane has to be cleaned before a coating will hold on to it.
Under the acrylic system

On EPDM the acrylic build-up is this wash primer, then KST041321, the gray single-ply acrylic base coat, then an acrylic finish coat such as KST041300.
Under Silicone44

On EPDM the silicone build-up is this wash primer, rinsed off and dried, open seams and flashings sealed with the black MS hybrid KST058310, then Silicone44 KST044300 (white) or KST044320 (gray) with no base coat.
Seam and detail preparation

Run across the seams, fastener plates, curbs and penetrations along with the field, so the detail work that follows lands on a cleaned surface.
Large flat roofs

Warehouse, retail and institutional EPDM roofs where the area is big, the access is poor and a full tear-off is the expensive option.

Specifications

Specifications: KST038620 Uniflex Bond-It Wash Primer, Clear
Manufacturer	Sherwin-Williams (Uniflex line)
Part number	KST038620
Color	Clear
Pack sizes	5-gallon pail
Not for	TPO, PVC, Hypalon (CSPE)

Performance
Technology	100% water based
Recommended substrates	Weathered EPDM, ahead of a coating system; not white EPDM
Role in the system	Cleaner primer

Ordering
SKU	CY-KST038620
Sold by	Pail
Lead time	In stock · 1–3 business days
Warranty	Goods are warranted to match their description and to be free of manufacturing defects when delivered; any manufacturer system warranty is issued by the manufacturer under its own terms

Delivery and lead time

Ships in 1–3 business days from order confirmation. Your quote states the delivery window before you commit.
Pails, rolls and cartons ship by parcel or pallet; drums and totes by freight to your site. Tell us about lift-gate, access or unloading needs when you ask for a quote.

Shipping & returns

How to order

Send the quantity, the site ZIP and your timing.
A person sends one written quote with the delivered price and the ship window. We reply within one business day.
Confirm the quote, and your order ships in 1–3 business days from confirmation.

Request a quote

Questions

Is this a cleaner or a primer?: The manufacturer describes it as a cleaner primer, which is why it exists. On an EPDM roof the wash-down and the priming are the same operation: it goes on, is rinsed off and the roof is left to dry. The data sheet states how it is applied and what it is applied over.
What goes on after it?: Under the acrylic system, KST041321, the gray single-ply acrylic base coat, which then has to be topcoated with an acrylic finish coat such as KST041300. Under silicone, nothing but the seam work: open seams and flashings sealed with the black MS hybrid KST058310, then Silicone44 KST044300 (white) or KST044320 (gray) with no base coat.
Does it work on TPO, PVC or Hypalon?: No. The current data sheet makes it an EPDM product, and not for white EPDM. Under the acrylic system, TPO, PVC and Hypalon are pressure washed and go straight to the single-ply base coat KST041321; weathered TPO and PVC take Silicone44 directly after an adhesion test. For sealant work on TPO and PVC there is a separate adhesion promoter, KST058700.
Is it for new EPDM?: No. It is for weathered EPDM. New membrane that has not weathered takes a different primer under a coating, so tell us the age of the roof and ask us before you order.
Is it solvent based?: No. The manufacturer states 100% water based for this primer. The solvent-based materials in this catalog are called out on their own pages and they ship differently.
How much do I need?: Coverage comes from the manufacturer product data sheet and depends on the membrane and its condition. Send the roof area, the membrane type and the site ZIP through the quote form and the quote states the pail count, the delivered price and the ship window.