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IndustryABOUT OTTO
  1. Construction
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  4. OTTOSEAL® sealants
  5. Silicone smoothing agent

Silicone smoothing agent

Tiles and natural stones are valuable wall and floor coverings. Ultimately perfect grouting completes the appearance. With our OTTO sealants and the optimally matched OTTO smoothing agents, we offer you the well-rounded range to be able to make perfect joints.

In this article you will learn::

  1. How to smooth silicone
     
  2. Silicone smoothing agent vs. washing-up liquid
     
  3. OTTO smoothing agent and the OTTO smoothing agent concentrate
     
  4. Smoothing agent applications

Smoothing silicone

With these instructions, smoothing silicone joints becomes a breeze.

1. Prepare the substrate

Prepare the substrate by masking and cleaning if necessary and backfilling the joint with suitable OTTO back-up foam rod.

2. Clean the substrate

Clean the substrate with OTTO Cleaner T and prime if necessary.

To the product

3. Grouting a project

Grout your project with a suitable OTTOSEAL® sealant.

View the OTTOSEAL® sealants

4. Selecting the right smoothing agent

Choose the right smoothing agent for you from our smoothing agent range

View all OTTO smoothing agent

5 & 6. Wet the smoothing tool & smooth the joint

Wet your smoothing tool with OTTO smoothing agent and then smooth the joint

7. Remove smoothing agent residues & remove adhesive tape

Remove excess smoothing agent residues and remove the adhesive tape.

Silicone smoothing agent vs. washing-up liquid

Smoothing with washing-up liquid

Smoothing with washing-up liquid is not a good idea, because washing-up liquid has a grease-dissolving effect. If the joint is smoothed with washing-up liquid, there is a risk that sealant components will be dissolved from the surface. This makes it dull and matte and when cleaning later, this can result in further abrasion of the sealant with unsightly streaks. When smoothing with washing-up liquid, the mixing ratio is often such that only a little washing-up liquid is dissolved in the water. Therefore, the smoothing ability is severely limited. The surfactants contained in commercial washing-up liquids remain visible as white stains  as residue on the surface of the sealant.

Grouting natural stone with washing-up liquid

If washing-up liquid is used when grouting natural stone, there is a great risk that these stains will get onto the natural stone surface and can no longer be removed from the stone. Washing-up liquids also contain grease-dissolving substances. These also strip the skin of its natural oil and damage the skin's protective acid mantle. This can result in skin irritation.

Smoothing with OTTO smoothing agents


In contrast, our OTTO smoothing agents do not contain any grease-dissolving substances, so they do not attack the skin and can be used safely.

Smoothing agent range

In our professional smoothing agent range you will find the right product for every application.

OTTO Smoothing agent spray

The smoothing agent spray
  • Optimally tailored to hybrid sealants
  • Immediately ready for use
  • Refillable
Technical datasheet

OTTO Smoothing Agent

The smoothing agent
  • Optimally tailored to OTTOSEAL® sealants
  • Ready for use
  • Gentle on your skin
  • Can be thinned with water (2 smoothing agents : 1 water)
Technical datasheet

OTTO Concentrated smoothing agent

The smoothing agent concentrate
  • Optimally tailored to OTTOSEAL® sealants
  • Can be individually matched
  • Gentle on your skin
Technical datasheet

OTTO Natural stone smoothing agent

The natural stone silicone smoothing agent
  • Ideal for natural stone applications
  • Ready for use
  • Gentle on your skin
Technical datasheet

Application with OTTO smoothing agents

Dilution according to application

OTTO smoothing agent can be diluted in a ratio of 2 parts smoothing agent to 1 part water. This mixture achieves a very pleasant smoothing of the joint surface. The OTTO concentrated smoothing agent can be individually thinned with water depending on the sealant and application. With all OTTO smoothing agents, the surfaces are optimally smoothed, resulting in the desired surface strength and silky sheen.

 

Natural stone application

  • Only use OTTO natural stone smoothing agent for the application of natural stone 
  • This may also only be applied undiluted to the joint.
  • After grouting with OTTO natural stone sealants, the sealant is modelled with OTTO Natural Stone Smoothing Agent.
  • It is recommended to use the smoothing agent as sparingly as possible, e.g. to wet the smoothing tools only lightly. To avoid stains/discolouration on the natural stone, excess smoothing agent should be removed with clean water before drying.

Smoothing with the OTTO smoothing agent spray

  • The OTTO smoothing agent spray has been optimally adapted to the smoothing of hybrid sealants, but can also be used for silicone and PU sealants.
  • With the spray bottle, this is immediately ready for use. The OTTO smoothing agent spray is also refillable and can be easily refilled with 20% OTTO smoothing agent concentrate and 80% water.
  • Normally before filling, the joint should be accurately masked off in the area of the joint edge zone with an adhesive tape suitable for the substrate. Especially in the case of rough, textured or visually sensitive surfaces, this is important in order to avoid the risk of marginal staining by foreign substances.
  • After smoothing, the smoothing agent residues remaining in the marginal area must be removed to avoid marginal contamination due to dried smoothing agent residues on the component surface.

Special application cases

Matte and matte sanded sealants and textured surfaces

  • When smoothing OTTO matte, matte sanded and textured sealants, the joint should only be skimmed once with a smoothing tool that has been dipped in OTTO smoothing agent. The more often the surface is reworked with smoothing agent, the more the matte effect is lost and the joint becomes glossier.
  • When smoothing matte sanded shades with the matching OTTO smoothing agent, it should also be noted that it is not recommended to smooth the joint with a finger, as this presses the sand particles into the sealant and they are no longer visible on the surface. For this application, we therefore recommend our OTTO smoothing tools as the perfect addition

Smoothing the glass rebate sealant on windows

When smoothing the glass rebate sealant with OTTO smoothing agent, we recommend a ratio of 2 parts OTTO smoothing agent and 1 part water. It should be noted that any water streaks created must be removed immediately after sealing. If cleaning is carried out at a later stage, there is a risk of leaving streaks that can no longer be removed.

OTTOSEAL® S 50 - the crystal clear silicone

Due to its crystal clear nature, OTTOSEAL® S 50 is sensitive to smoothing agents. Slightly milky cloudiness may form. If possible, no smoothing should be done at all, or only very heavily diluted soft soap solution should be used.

To the product

Metallic colours

  • When working with OTTO sealants with a "metallic effect" (e.g. in the colour shade C197 stainless steel, C14 aluminium, RAL 9006 or RAL 9007, etc.), care must be taken that no layers are pushed over each other when shaping, but that the top layer is removed so that a smooth surface is created.
  • Otherwise, sliding one layer over the other, e.g. in the corner area, could result in dark, clearly visible dividing lines. These lines cannot be removed by subsequent smoothing. The reason for this is the colour pigment that creates the metallic effect. This is a typical product characteristic of the metallic shades and is not a product defect.

Do you have questions about our OTTOSEAL® sealants?

Our application consultation is available Monday to Thursday from 7:00 a.m. to 4:00 p.m. and Friday from 7:00 a.m. to 1:00 p.m. and will be happy to receive your request.

+49 8684 908 4300[email protected]Ask a question

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