Quick answer: buyers working on waterborne wood sealers usually get better results when they split the first question into three different jobs instead of asking for one additive to do everything. Start with CHLUMICRYL® WD-D545 when the sealer still struggles with first-contact wetting and spread on the wood surface. Start with CHLUMILE® 3345 when the sealer already enters the surface directionally but still needs calmer wetting and leveling. Start with CHLUMICRYL® DF-D9904BR when the main visible defect is trapped air, microbubbles, or pinholes in the water-based sealer film.
This page is intentionally narrower than a broad waterborne wood coating additives guide and earlier than a wood varnish additives page. The buyer question here is the sealer-stage decision: what should you use when the first waterborne sealing coat still is not entering, settling, or releasing air the way the downstream topcoat needs?
Shortlist: three practical additive routes for waterborne wood sealers
| Additive route | Best fit | What it helps you solve first |
|---|---|---|
| CHLUMICRYL® WD-D545 | Waterborne wood sealer systems that need cleaner substrate entry and spread | First-contact wetting, spreading, and lower surface-tension entry on the wood-facing sealer layer |
| CHLUMILE® 3345 | Waterborne sealers that already wet directionally but still look uneven or unsettled | Broader wetting-and-leveling cleanup for a calmer sealer film before the next coat |
| CHLUMICRYL® DF-D9904BR | Water-based sealers where entrained air, microbubbles, or pinholes are distorting the film read | Bubble suppression, microbubble cleanup, and pinhole reduction in water-based application |
The logic is simple. If the sealer still is not meeting the wood surface correctly, start with wetting. If it already meets the surface but still lays down roughly, move toward wetting-and-leveling cleanup. If the bigger problem is visible air in the film, stop forcing more spread additives first and fix the bubble route.
When CHLUMICRYL® WD-D545 is the better fit
CHLUMICRYL® WD-D545 is the stronger starting point when the first sealer coat still looks like a surface-entry problem. Longchang supports it as a polyether modified polydimethyl siloxane route for water-borne wood paint, industrial paint, and plastic paint, with wetting and spreading support plus strong surface-tension reduction. The company page also publishes a direct 20.5 mN/m at 0.2% in water reference point, which is useful when your main question is still early substrate contact instead of final-film feel.
Use this route first when:
- the sealer still hesitates or breaks on the surface at first contact
- you need a stronger wetting-first screen before you judge downstream leveling or topcoat behavior
- you are still trying to build a cleaner first sealing layer before the next coat
Longchang’s product page supports these practical handling points for WD-D545:
- application fit: water-borne wood paint is directly listed
- function: wetting and spreading support with strong surface-tension reduction
- dosage: 0.1% to 0.5%
- addition timing: can be added during grinding, paint blending, or after production
- stability note: low-temperature freeze can recover after thawing and stirring evenly
If your waterborne wood sealer still looks like it is not entering the surface cleanly enough to judge anything else, WD-D545 is usually the right first screen. If the surface already wets directionally and the complaint has become more about overall film calmness, shift to 3345 instead of staying trapped in a wetting-only loop.
When CHLUMILE® 3345 is the better fit
CHLUMILE® 3345 becomes the better fit when the buyer problem is no longer just “can the sealer wet the surface?” but rather “can the sealer form a smoother, calmer film?” Longchang supports 3345 as a wetting and leveling agent based on polyether modified polysiloxane chemistry, with use across water, oil, and UV systems. The product page also supports flexible addition timing during grinding, stirring, or after production, plus the practical note that co-solvents such as dipropylene glycol methyl ether can enhance the effect.
Use 3345 first when:
- basic surface entry is already acceptable but the sealer still looks uneven
- you want a broader wetting-plus-leveling route instead of a stronger first-contact wetting route
- the first sealer layer needs calmer laydown before a topcoat, varnish, or later finishing step
Longchang’s supported handling points for 3345 include:
- function: wetting and leveling
- system range: water, oil, and UV
- dosage: 0.1% to 1.0%
- addition timing: grinding, stirring, or after production
- practical note: some co-solvents can enhance the effect
This is the lane to use when the conversation has moved beyond raw substrate entry and into visible film cleanup. For buyers already dealing with a sealer coat that forms but still reads unsettled, 3345 is usually the cleaner next screen than forcing a defoamer-first or anti-sticking-first solution.
When CHLUMICRYL® DF-D9904BR is the better fit
CHLUMICRYL® DF-D9904BR should move to the front of the shortlist when the waterborne wood sealer is being judged mainly by microbubbles, trapped air, or pinholes. Longchang supports DF-D9904BR as a silica-free polyether modified polysiloxane defoamer for water-based systems, with direct language around preventing microbubbles and pinholes.
Use DF-D9904BR first when:
- the sealer film already wets directionally but still looks full of tiny trapped-air marks
- you keep seeing bubble-related surface defects after application or mixing
- the defect pattern is telling you this is more an air-release problem than a pure wetting or leveling problem
Longchang’s supported handling points for DF-D9904BR include:
- system boundary: water-based systems
- function: prevent microbubbles and pinholes
- dosage: 0.1% to 1.0%
- incorporation: add under high-speed stirring or with a grinding machine
- practical note: incorporate via co-solvent first when possible for easier dispersion
If your sealer panel is being rejected because air is still sitting in the film, this route is usually more useful than adding more wetting or leveling material and hoping the defect disappears indirectly. If the real blocker is trapped air, treat it as trapped air.
How buyers should choose between wetting, leveling, and bubble control in a wood sealer stage
A useful screening order for waterborne wood sealers is:
- Check the first-contact read. If the sealer still is not entering or spreading cleanly, start with WD-D545.
- Check the formed film. If the sealer already wets but still settles unevenly, move toward 3345.
- Check the defect pattern. If the visible problem is microbubbles or pinholes, move DF-D9904BR to the front.
This stage-specific split is why a sealer page deserves its own place in the CHLUMICRYL branch. A broad wood-coating page often has to cover too many jobs at once. A waterborne wood sealer buyer usually needs a tighter decision: build a cleaner first sealed layer now, then hand the project forward to later finish steps with fewer unknowns.
Where this page fits in the broader CHLUMICRYL® branch
If the work is broader than the sealer stage, these related pages usually help:
- How to Choose Additives for Waterborne Wood Coatings for a wider waterborne wood route
- How to Choose Additives for Wood Varnishes for later finish-film selection
- How to Choose Additives for Waterborne Topcoats for finish-layer laydown, handling, and bubble cleanup
- How to Choose Additives for Coating Pinholes when the defect diagnosis itself still is not clear
Relevant product pages for this sealer-stage shortlist are:
FAQ: Waterborne wood sealer additive selection
Do waterborne wood sealers need the same additive logic as wood varnishes?
Not always. A waterborne wood sealer usually is judged earlier in the build, where first-contact wetting, early film formation, and trapped-air cleanup can matter before later finish-film feel or final appearance tuning.
When should I screen WD-D545 before 3345?
Screen WD-D545 first when the main issue still looks like surface entry or spreading. If the sealer already enters the surface directionally and the bigger complaint is calmer laydown, 3345 is usually the more relevant next route.
When is DF-D9904BR more useful than another wetting additive?
When the visible problem is microbubbles or pinholes in a water-based sealer film. In that case, a defoamer route is usually more direct than continuing to optimize wetting first.
Can these routes replace formulation testing?
No. They help narrow the first screening direction, but final dosage, incorporation order, and full formulation compatibility still need lab validation in your own waterborne wood sealer system.
Next step
If your team is building a waterborne wood sealer shortlist, start by deciding whether the first bottleneck is substrate-entry wetting, overall sealer-film calmness, or microbubble and pinhole cleanup. That split usually gets you to a better first sample set faster than treating every sealer defect as the same additive request.