PTFE Tape Surface Compatibility Checker

Yes. Clean stainless steel is the benchmark surface for silicone-adhesive PTFE tape, and it needs no primer and no abrasion.

What decides the bond

The peel strength printed on a tape data sheet is measured on polished 304 stainless steel cleaned with solvent alone (ASTM D3330), so this is the surface those numbers describe. On a real part, what gets in the way is whatever sits on the steel: machining oil, fingerprints, heat tint or old adhesive.

A brushed No.4 finish can be more than ten times rougher than that test panel, so rub the tape down firmly along its length.

How to prepare it

1. If the surface is oily, degrease it first.
2. Wipe it two or three times with IPA on fresh lint-free cloths. On a brushed finish, wipe along the polish lines.
3. Only if there is heat tint or baked-on residue, take it off with a fine non-woven pad or 180 to 320 grit paper, then wipe with IPA again.
4. Let the IPA evaporate completely, keep fingers off the cleaned area and tape it the same day.

Avoid

• Sanding or etching clean stainless steel. The tape does not need it.
• Spray lubricants such as WD-40 as a cleaner. They leave a film.

Yes. Clean bare aluminium takes silicone-adhesive PTFE tape well, with no primer.

What decides the bond

Aluminium always carries a thin natural oxide, and the adhesive bonds to it without any special treatment. The problems are rolling or cutting oil on new stock, and thick, chalky or heat-discoloured oxide on older parts.

Abrasion is only for those cases, and chemical etches belong to structural adhesives, not tape. What matters most is taping soon after the final clean.

How to prepare it

1. Degrease new or machined parts to remove rolling or cutting oil.
2. Wipe with IPA on a lint-free cloth until the cloth comes away clean.
3. Only if there is white corrosion, heavy or discoloured oxide, or stuck residue: scuff with a fine non-woven pad or 180 to 320 grit, then wipe with IPA again.
4. Let it dry fully and apply the tape in the same work session.

Avoid

• Coarse sanding or grinding. Deep scratches are more texture than a thin tape adhesive can fill.
• Primers and chemical etches. They are for structural adhesives, not tape.

Usually good. A clean, well-sealed anodised surface takes tape much like bare aluminium, but some sealing faults make tape lift.

What decides the bond

Anodising grows a hard oxide layer and then seals its pores. 3M notes that adhesion to anodised aluminium depends on the structure of that layer and the type of sealer used, and anodising specialists have traced adhesive failures on black anodise to surfactants in the sealer and to a powdery “sealing smut” left on the surface.

PTFE-impregnated hard anodise is a different case. It is a non-stick surface, so choose the non-stick coated metal option instead.

How to prepare it

1. Degrease if oily, then wipe with IPA.
2. If a clean cloth picks up a grey or coloured powder, keep wiping gently with fresh cloths until it comes away clean.
3. Let it dry fully, then apply.

Avoid

• Abrading the anodised layer. On a jaw it is there for wear resistance or electrical insulation.
• Relying on a water-break test. 3M notes it is unreliable on anodised aluminium.

Trial it first: press a short strip onto the real surface, leave it a day (and put it through a heat cycle if it will run hot), then peel it. Firm, even resistance with nothing left behind is a pass. An easy, clean release, or paint, fibres or coating coming away with the tape, is a fail.

Fair. Die-cast parts often carry wax or silicone release agent from the mould, and cast surfaces can be porous.

What decides the bond

Die-casting release agents are wax emulsions and silicone oils, and they can take a lot of cleaning to remove, even before painting. A porous casting can also hold oil or solvent below the surface.

How to prepare it

1. Wash with a detergent or solvent degreaser to remove release agent, repeating until a clean cloth stays clean.
2. Scuff lightly through the as-cast skin with a fine non-woven pad or 180 to 320 grit.
3. Wipe twice with IPA on fresh cloths and allow extra drying time.

Avoid

• Silicone sprays or release agents anywhere near the part before taping.

Trial it first: press a short strip onto the real surface, leave it a day (and put it through a heat cycle if it will run hot), then peel it. Firm, even resistance with nothing left behind is a pass. An easy, clean release, or paint, fibres or coating coming away with the tape, is a fail.

Good on clean, bright steel. The failures come from what is on it: mill scale, rust, rust-preventive oil and spray lubricants.

What decides the bond

New steel usually carries a rust-preventive oil and often mill scale, and older steel carries rust. Alcohol on its own does not shift grease, so degrease before the IPA wipe. Bare steel starts to rust quickly once cleaned, so tape it promptly.

How to prepare it

1. Degrease to remove oil and any spray lubricant film.
2. Remove mill scale and rust back to bright metal, finishing with 180 to 320 grit or a fine non-woven pad so no coarse scratches remain.
3. Wipe with IPA until the cloth stays clean.
4. Tape it the same day, before any flash rust forms.

Avoid

• WD-40 and similar sprays before taping. Its maker says it leaves a thin coating.
• Coarse grinding marks. A thin tape adhesive cannot fill them.

Heat: On jaws held at 150 to 250 °C for hours, conventional silicone adhesive can split when the tape is peeled off and leave residue on iron and copper-based metals (Shin-Etsu). Expect to clean off residue at each tape change.

Fair. Cast iron is porous and holds oil, which keeps seeping back to the surface after you clean it.

What decides the bond

The graphite in cast iron leaves a porous surface that coatings makers flag for poor wetting and adhesion, and oil soaked into those pores comes back after one wipe. It needs repeated degreasing.

How to prepare it

1. Degrease repeatedly until a clean cloth stays clean.
2. Abrade to sound metal, finishing with a fine grade.
3. Degrease again, wipe with IPA, let it dry fully and tape promptly.

Avoid

• Assuming one wipe is enough. Absorbed oil comes back.

Heat: On jaws held at 150 to 250 °C for hours, conventional silicone adhesive can split when the tape is peeled off and leave residue on iron and copper-based metals (Shin-Etsu). Expect to clean off residue at each tape change.

Trial it first: press a short strip onto the real surface, leave it a day (and put it through a heat cycle if it will run hot), then peel it. Firm, even resistance with nothing left behind is a pass. An easy, clean release, or paint, fibres or coating coming away with the tape, is a fail.

Fair. Tape bonds to freshly cleaned copper alloys, but they keep tarnishing under the tape, and on hot jaws the adhesive tends to leave residue.

What decides the bond

3M warns that copper and brass keep oxidising even after tape is applied. Heat makes it worse: a Shin-Etsu patent on heat-resistant silicone tape found that conventional silicone adhesive held at 150 to 250 °C on copper, copper alloys or iron splits when peeled and leaves residue. On polished copper at 200 °C, residue covered the whole plate after three hours.

Residue on a hot brass or copper jaw at tape change is therefore a documented heat-ageing effect, and it has to be cleaned off completely before the next tape goes on.

How to prepare it

1. Degrease if oily.
2. Remove tarnish with a fine non-woven pad just before taping, so the tape goes onto bright metal.
3. Wipe with IPA and let it dry.
4. At every tape change, remove all the old adhesive before re-taping.

Avoid

• Sanding beryllium copper without dust extraction. Its dust is a serious lung hazard, so clean it with solvent only.
• Lacquering a heated jaw against tarnish. Lacquer is a fix for cold copper parts, not hot ones.

Fair. The zinc itself is sound, but oils, passivation treatments and white rust sit between it and the tape.

What decides the bond

Galvanised steel is often treated with oils or passivation films after galvanising, and damp storage produces white rust, a powdery zinc oxide several times the volume of the zinc it came from. Sources disagree on how well passivated zinc bonds, so run a trial strip.

How to prepare it

1. Remove white rust with a stiff nylon brush and a mild cleaner such as white vinegar, then rinse and dry fully.
2. Degrease, then wipe with IPA.
3. Press on a trial strip. If it lifts cleanly, scour lightly with a non-metallic pad, clean again and retest.

Avoid

• Wire brushes and heavy abrasion, which damage the zinc coating.

Trial it first: press a short strip onto the real surface, leave it a day (and put it through a heat cycle if it will run hot), then peel it. Firm, even resistance with nothing left behind is a pass. An easy, clean release, or paint, fibres or coating coming away with the tape, is a fail.

Good when clean, although no tape maker publishes data for plated surfaces.

What decides the bond

Chrome and nickel plate are hard, passive metal surfaces, much like stainless steel. The usual contaminants are polishing compound and oil. Where the plating has worn through, the tape lands on the base metal, often copper or brass, and inherits its problems.

How to prepare it

1. Degrease to remove oil and polishing compound.
2. Wipe with IPA until the cloth stays clean, then let it dry.

Avoid

• Abrading the plating. Going through it exposes the base metal.

Trial it first: press a short strip onto the real surface, leave it a day (and put it through a heat cycle if it will run hot), then peel it. Firm, even resistance with nothing left behind is a pass. An easy, clean release, or paint, fibres or coating coming away with the tape, is a fail.

Not recommended. A non-stick coating is a release surface by design, and silicone adhesive only holds weakly on it.

What decides the bond

PTFE’s surface energy is at or below the silicone adhesive’s own, so the adhesive barely wets it. In Dow Corning’s tests, conventional silicone adhesives kept only about 9 to 17% of their steel peel strength on Teflon. That is why tape makers chemically etch the back of PTFE film before coating it with adhesive.

Sanding does not fix it: roughening PTFE gives little or no gain, and it ruins the coating.

What to do instead

1. Use the coated surface as the non-stick face it already is, without tape.
2. If the coating is worn out, have it stripped back to bare metal, then prepare the metal as bare aluminium or steel.

Avoid

• Taping over the coating, or sanding it to make tape stick.

Heat sealing jaws are commonly aluminium, brass, copper or steel, and silicone-adhesive PTFE tape works on all of them. Identify the metal, then follow the rules below, which apply to every jaw.

How to tell what the jaw is made of

A magnet sticks firmly to mild steel and cast iron. It does not stick to aluminium, brass or copper, and only weakly or not at all to most stainless steel. Brass looks yellow-gold, copper reddish, and aluminium is light grey and noticeably lighter in the hand. A matt or coloured finish on aluminium usually means it is anodised.

Serrated, knurled or grooved jaw faces are not covered by any published guidance. Ask us before taping one.

Rules for every jaw

1. Switch off, unplug an electrically heated sealer and let the jaw cool to room temperature before any solvent goes near it. Isopropyl alcohol has a flash point of about 12 °C.
2. Remove all old tape and adhesive. New tape laid over old tape sits on untreated PTFE and holds poorly.
3. Clean with high-strength IPA and no added water. Impulse sealer makers say never to use moisture on the sealing surface.
4. Apply the tape from one end with firm, even pressure and no trapped air, extending it past both ends of the heated area.
5. On impulse sealers, zone tape keeps adhesive off the heating element, so it comes away clean at the next change.

Avoid

• Taping or solvent-cleaning a warm jaw.
• Silicone spray on the jaw. It stops the next tape from bonding.

• Zone tapes for impulse sealer elements
• Step-by-step heat sealer tape replacement

Good. Clean glass is a high-energy surface that silicone adhesive bonds to well, once invisible films are removed.

What decides the bond

The risks on glass are the ones you cannot see: wax from some window cleaners, silicone films and, in humid conditions, a thin film of water. A water-drop check shows whether a film is there. If the drops bead up instead of spreading out, the glass is not clean yet.

Coated glass (low-e, reflective or tinted) has a different surface, so trial it first.

How to prepare it

1. Put a few drops of water on the glass. If they bead, remove the film with a mild, wax-free glass cleaner, then carry on.
2. Wipe with IPA mixed with water on one cloth and dry it straight away with a second clean cloth (the “two cloth” method).
3. Tape a dry pane at room temperature.

Avoid

• Household window cleaners as the final wipe. Some contain waxes.
• Abrading glass. It weakens it.

Good. A glaze is a fired glass layer, and it takes tape the way glass does.

What decides the bond

3M groups glazed tile with glass for both cleaning and humidity. Unglazed ceramic is different: it is porous and needs sealing first, so choose the concrete, brick and stone option. Dense technical ceramics such as alumina have no published tape data. They are likely to behave like glass, but trial them.

How to prepare it

1. Check with a few drops of water, as for glass. If they bead, clean off the film first.
2. Wipe with IPA mixed with water, then dry straight away with a second clean cloth.
3. Tape it dry and at room temperature.

Avoid

• Household cleaners as the final wipe.
• Abrading the glaze.

Good. Silicone tape holds on polycarbonate about as well as on steel, but the wrong solvent will crack the plastic.

What decides the bond

3M’s silicone-adhesive tape 96042 holds 4.4 N/cm on polycarbonate, the same as on stainless steel. The risk is the cleaner: polycarbonate stress-cracks when solvents such as acetone get into its surface, and Covestro, which makes Makrolon polycarbonate, notes that solvent trapped under a tape edge counts as prolonged exposure.

How to prepare it

1. Wash off dirt with mild detergent and water if needed, and dry.
2. Wipe briefly with IPA on a lint-free cloth.
3. Let it dry fully. Polycarbonate absorbs a little water, so dry the part before hot service.

Avoid

• Acetone, MEK, toluene, xylene and methanol.

Heat: Polycarbonate’s own continuous service limit is about 116 to 135 °C (Henkel). The tape is rated higher, so the plastic sets the limit.

Good adhesion, but acrylic is the most solvent-sensitive plastic on this list. Do not clean it with IPA.

What decides the bond

Silicone adhesive wets acrylic readily. The problem is cleaning it: Röhm, which makes PLEXIGLAS, rates ethanol and other alcohols as unsuitable for it, and ketones and aromatic solvents craze it. Clean it with soapy water, or heptane for oily films.

How to prepare it

1. Wash with mild soapy water, rinse with clean water and dry with a soft lint-free cloth.
2. For an oily film, wipe with heptane and let it evaporate fully.
3. Apply at room temperature.

Avoid

• IPA and other alcohols, acetone, MEK and toluene.
• Abrading. Henkel found it gave no benefit on acrylic.

Heat: Acrylic’s continuous service limit is only about 77 to 88 °C (Henkel), far below the tape’s.

Good. Both are medium-energy plastics that silicone adhesive wets easily.

What decides the bond

3M’s silicone-adhesive tape 96042 holds 4.4 N/cm on ABS, the same as on stainless steel. Rigid PVC has no published silicone tape data but sits in the same surface energy range. Watch the solvent: ketones attack both, and hydrocarbons attack PVC.

How to prepare it

1. Wash off dirt with detergent and water if needed, and dry.
2. Wipe with IPA and let it dry.

Avoid

• Acetone, MEK and other ketones or esters.
• Hydrocarbon solvents on PVC.
• Sanding rigid PVC. Henkel found it gave no benefit.

Heat: ABS is rated for continuous service to only about 54 to 82 °C, and rigid PVC to about 54 to 104 °C (Henkel), far below the tape.

Poor to fair. Flexible PVC contains plasticiser that migrates into pressure-sensitive adhesives and softens them.

What decides the bond

Plasticised vinyl can be 15 to 50% plasticiser, and plasticiser moving into an adhesive softens it until it turns gummy. One silicone adhesive maker claims silicone resists this better than acrylic, but it publishes no test data, so test before relying on it. Heat speeds the migration up.

How to prepare it

1. Wipe with IPA only, and let it dry.
2. Bond a sample, keep it at 66 °C for seven days, then check for softening, discolouration or lifting. This is 3M’s accelerated check for plasticiser problems.

Avoid

• Solvents stronger than IPA.
• Hot service without that test.

Trial it first: press a short strip onto the real surface, leave it a day (and put it through a heat cycle if it will run hot), then peel it. Firm, even resistance with nothing left behind is a pass. An easy, clean release, or paint, fibres or coating coming away with the tape, is a fail.

Fair. Silicone adhesive wets these low-energy plastics where standard acrylic adhesives struggle, but it holds less firmly than on metal.

What decides the bond

Polypropylene and polyethylene sit at about 29 to 31 mN/m, just above silicone adhesive’s roughly 20, so the adhesive can wet them. How hard it then holds depends on the adhesive: 3M’s silicone tape 96042 holds 3.8 N/cm on polypropylene against 4.4 on steel, and in Dow Corning’s tests the peel on polyethylene varied more than tenfold between silicone formulations.

If a trial strip peels too easily, flame, corona or plasma treatment raises the surface energy. Those treatments are proven with other adhesives rather than tested with silicone, so trial again afterwards.

How to prepare it

1. Wipe with IPA and let it dry.
2. Press a trial strip on firmly and peel it after a day.
3. If the bond is too weak, have the surface flame, corona or plasma treated, and tape it promptly afterwards.

Avoid

• Hydrocarbon solvents such as hexane and toluene.
• Sanding. Henkel found it gave no benefit on polyethylene.

Heat: Polyethylene’s continuous service limit is only about 40 to 70 °C (Henkel).

Trial it first: press a short strip onto the real surface, leave it a day (and put it through a heat cycle if it will run hot), then peel it. Firm, even resistance with nothing left behind is a pass. An easy, clean release, or paint, fibres or coating coming away with the tape, is a fail.

Good, once the part is dry. Nylon soaks up water, and moisture escaping under the tape in hot service can lift it.

What decides the bond

Nylon has a relatively high surface energy, about 46 mN/m on 3M’s chart, which silicone adhesive wets easily. It can also absorb up to 3% water in 24 hours (Henkel), and 3M warns that plastic which has not been dried properly can bubble under an applied film when it is heated.

How to prepare it

1. Dry the part if it has been stored somewhere humid, especially before hot service.
2. Wipe with IPA and let it dry.

Avoid

• Taping a damp part that will run hot.

Fair. Acetal is a notoriously difficult plastic to bond, even though silicone adhesive can wet it.

What decides the bond

Acetal sits at about 36 mN/m on 3M’s chart, within reach of silicone adhesive, but it is known as a hard plastic to bond. Henkel found light abrasion helped or did no harm on acetal. If a trial strip still peels too easily, flame treatment can help.

How to prepare it

1. Wipe with IPA and let it dry.
2. Scuff lightly with a fine abrasive, then wipe with IPA again.
3. Trial a strip. If the peel is low, flame-treat the surface and tape it promptly.

Avoid

• Sandpaper with lubricant in it. Henkel warns that some does.

Trial it first: press a short strip onto the real surface, leave it a day (and put it through a heat cycle if it will run hot), then peel it. Firm, even resistance with nothing left behind is a pass. An easy, clean release, or paint, fibres or coating coming away with the tape, is a fail.

Good. PET film is one of the standard backings that silicone adhesives are coated onto.

What decides the bond

Silicone adhesives are routinely coated onto PET and polyimide films, and PET’s surface energy, about 43 mN/m on 3M’s chart, is well above the adhesive’s. Henkel found abrading PET gave no benefit, so clean it rather than sand it.

How to prepare it

1. Wipe with IPA and let it dry.
2. Apply with firm pressure.

Avoid

• Sanding. It does not improve the bond on PET.

Good, and these are the plastics that can run nearly as hot as the tape itself.

What decides the bond

Polyimide film is a standard backing for silicone-adhesive tapes, and both are high-energy, high-temperature plastics. Henkel gives continuous service limits of about 220 to 249 °C for PEEK and 249 to 288 °C for polyimide, close to the tape’s own 260 °C rating.

How to prepare it

1. Degrease machined parts to remove cutting fluid.
2. Wipe with IPA and let it dry.

Avoid

• Taping over machining oil.

Good. Phenolic and epoxy surfaces are medium to high energy and bond well once clean.

What decides the bond

Phenolic sits at about 47 mN/m and epoxy at about 43 on 3M’s chart, well above the adhesive. Machined laminates carry cutting fluid and fine dust, so clean them thoroughly. Henkel found abrasion helped or did no harm on epoxy.

How to prepare it

1. Blow or wipe off machining dust.
2. Wipe with IPA and let it dry.
3. If a trial strip lifts, scuff lightly, then clean again.

Avoid

• Acetone and other ketones on epoxy.

Not recommended. Untreated PTFE, FEP and PFA, including the top face of old PTFE tape, are release surfaces that silicone adhesive only holds weakly.

What decides the bond

Their surface energy, about 16 to 22 mN/m, is at or below the adhesive’s own. In Dow Corning’s tests, conventional silicone adhesives peeled from Teflon at roughly 1 to 2.5 N per 25 mm, against 9 to 15 on steel.

That is why tape makers chemically etch the back of PTFE film before coating it with adhesive, and sell tape etched on both sides for jobs where it must overlap itself. Only chemically etched PTFE takes tape well, and etching is not a shop-floor job.

What to do instead

1. Remove old tape and every trace of its adhesive before re-taping.
2. On wide surfaces, use one full-width self-adhesive PTFE sheet instead of overlapping strips, because an overlap lands on un-etched PTFE.
3. If a PTFE part itself has to carry tape, buy it pre-etched.

Avoid

• Putting new tape over old tape.
• Sanding PTFE to make tape stick. Roughening gives little gain.

• Full-width self-adhesive Teflon sheets

Good. Silicone rubber is where silicone adhesive does best, and where standard acrylic adhesives fail.

What decides the bond

3M says silicone tapes are best known for their ability to bond to silicone, and its silicone tape 96042 holds 3.8 N/cm on silicone rubber. The risks are in the rubber. Uncured low-molecular-weight silicone can migrate to the surface and interfere with adhesion, and post-cured rubber carries less of it. Common solvents other than IPA, including acetone, heptane and toluene, swell silicone rubber.

Thin silicone release coatings and silicone varnishes are a weaker case: they can carry free silicone oil or peel away with the tape, so trial them.

How to prepare it

1. Clean with IPA only.
2. Wipe off any oily film on new pads, and choose post-cured rubber where you have the option.
3. Let the IPA evaporate fully before taping.

Avoid

• Acetone, MEK, heptane, toluene and mineral turpentine. They swell silicone rubber.
• Solvent-based adhesive removers on the pad.

Poor to fair. Both rubbers contain oils and plasticisers that come to the surface and weaken the bond.

What decides the bond

EPDM has a low surface energy, about 32 mN/m, and 3M flags it for low adhesion. Rubber compounds carry process oils, plasticisers and antioxidants, which lowered bond strength in Henkel’s rubber bonding tests. Heat speeds that migration up, so hot EPDM or nitrile is a high-risk surface.

How to prepare it

1. EPDM: wipe with IPA or acetone. Nitrile: IPA only.
2. Bond a sample, keep it at 66 °C for seven days, then check for softening or lifting before relying on it.

Avoid

• On EPDM: heptane, hexane, toluene and mineral turpentine.
• On nitrile: acetone, MEK and toluene.

Trial it first: press a short strip onto the real surface, leave it a day (and put it through a heat cycle if it will run hot), then peel it. Firm, even resistance with nothing left behind is a pass. An easy, clean release, or paint, fibres or coating coming away with the tape, is a fail.

Fair. These bond better than EPDM, but oils and antioxidants in the compound can still come to the surface.

What decides the bond

3M lists migrating oils as the concern with neoprene, and natural rubber has a low surface energy of about 32 mN/m. Viton is a fluorinated rubber, not PTFE, and Shin-Etsu markets silicone adhesives for bonding to it.

How to prepare it

1. Neoprene and natural rubber: wipe with IPA or ethanol. Viton: IPA or heptane.
2. Trial a strip and check it after a few days, and after a heat cycle if it will run hot.

Avoid

• On neoprene: MEK and toluene.
• On natural rubber: MEK, heptane, toluene and mineral turpentine.
• On Viton: acetone and MEK.

Trial it first: press a short strip onto the real surface, leave it a day (and put it through a heat cycle if it will run hot), then peel it. Firm, even resistance with nothing left behind is a pass. An easy, clean release, or paint, fibres or coating coming away with the tape, is a fail.

Fair. PU bonds reasonably well, but it is the one common rubber you should not clean with IPA.

What decides the bond

Elastomer resistance charts rate IPA and other alcohols as harmful to polyurethane rubber, so clean it with mild detergent or heptane instead. 3M lists mould release as the main contaminant on PU parts, and Henkel found light abrasion helped or did no harm on polyurethane.

How to prepare it

1. Wash with mild detergent and water, or wipe with heptane for oily films, and dry fully.
2. If a trial strip lifts, scuff lightly, then clean again.

Avoid

• IPA and other alcohols, acetone and MEK.

Trial it first: press a short strip onto the real surface, leave it a day (and put it through a heat cycle if it will run hot), then peel it. Firm, even resistance with nothing left behind is a pass. An easy, clean release, or paint, fibres or coating coming away with the tape, is a fail.

Fair to good on fully cured, sound paint. The tape can never hold better than the paint holds onto the metal.

What decides the bond

Under-cured paint keeps releasing solvent, so paint makers typically recommend waiting about a week before taping, and two-pack polyurethane needs to cure above about 21 °C. Chalky, matt, anti-graffiti and silicone- or wax-modified paints are poor bases, and 3M says adequate adhesion to anti-graffiti paint “may not be possible”.

Painted metal is not a good base for tape on a heated jaw, because the bond cannot outlast the paint.

How to prepare it

1. Wait for the paint maker’s full cure time, typically about a week, not just until it is touch-dry.
2. Check the paint holds: press a strip of strong tape on, pull it back sharply, and make sure no paint or chalk comes away on it.
3. Wash off dirt with detergent, remove any oil with a solvent tested on a hidden spot first, then wipe with IPA mixed with water.
4. If you like, scuff gloss paint lightly with 180 to 320 grit in small circles, then clean again.
5. Leave a strip of the PTFE tape on for 24 hours at room temperature and look for bubbles, which mean the paint is still giving off solvent.

Avoid

• Taping paint that is only touch-dry.
• Strong solvents that soften the paint.

Trial it first: press a short strip onto the real surface, leave it a day (and put it through a heat cycle if it will run hot), then peel it. Firm, even resistance with nothing left behind is a pass. An easy, clean release, or paint, fibres or coating coming away with the tape, is a fail.

Fair, and it varies from one powder to the next, so always trial it.

What decides the bond

Powder coats can contain waxes, slip agents and other additives that weaken tape adhesion (3M), and one coater saw weaker bonds on gloss than on matt, and on black than on white. The finish alone does not predict the result, and the powder coat makers we checked publish no tape bonding guidance.

Ask your coater which product was used, and trial the tape on an offcut from the same batch.

How to prepare it

1. Make sure the coating is fully cured and has cooled to room temperature.
2. Clean in three stages: a detergent wash, a solvent wipe, then IPA.
3. Trial a strip. If it is weak, scuff lightly with a fine pad, clean again and retest.

Avoid

• Assuming one powder coat behaves like another.

Trial it first: press a short strip onto the real surface, leave it a day (and put it through a heat cycle if it will run hot), then peel it. Firm, even resistance with nothing left behind is a pass. An easy, clean release, or paint, fibres or coating coming away with the tape, is a fail.

Poor until sealed. Raw timber and board have an open, fibrous surface, so the tape grips loose fibres rather than a solid face.

What decides the bond

3M says wood, particleboard and similar materials have an open surface and need sealing to give tape a single, unified surface to bond to. Resinous timbers are poor candidates, and fibreboard can keep giving off gas for a long time. Once sealed with a hard, fully cured coat, treat it as a painted surface.

How to prepare it

1. Fill any voids and sand smooth.
2. Seal with two coats of a hard sealer, such as paint, varnish or two-pack polyurethane, letting each cure fully.
3. Then prepare it as a painted surface: fully cured, clean and trialled.

Avoid

• Taping raw timber, MDF or particleboard.
• Heavily resinous timbers.

Trial it first: press a short strip onto the real surface, leave it a day (and put it through a heat cycle if it will run hot), then peel it. Firm, even resistance with nothing left behind is a pass. An easy, clean release, or paint, fibres or coating coming away with the tape, is a fail.

Poor unless sealed. These surfaces are dusty, porous and often damp, and new concrete is strongly alkaline.

What decides the bond

3M’s guidance is to let new concrete cure for 6 to 12 months to lose its strong alkali, to wire-brush off loose material, or to seal it. Unglazed ceramic and terracotta fall under the same porous-surface rule. Water-break and dyne tests give false readings on absorbent surfaces, so do not rely on them here.

How to prepare it

1. Wire-brush off loose material and dust.
2. Make sure the surface is dry.
3. Seal it with a hard coating and treat it as painted, or on new concrete, wait for it to cure.

Avoid

• Taping damp or dusty masonry.

Trial it first: press a short strip onto the real surface, leave it a day (and put it through a heat cycle if it will run hot), then peel it. Firm, even resistance with nothing left behind is a pass. An easy, clean release, or paint, fibres or coating coming away with the tape, is a fail.

Good on tightly woven glass cloth and fabric, which are established silicone adhesive surfaces.

What decides the bond

Dow lists glass cloth, fabric and silicone-varnished cloth among the surfaces its silicone adhesives bond to. Open weaves give the adhesive less to hold. Any PTFE-coated fabric, such as an old PTFE belt or sheet, is a PTFE surface, not a fabric one.

How to prepare it

1. Brush or vacuum off dust and loose fibres.
2. Make sure it is dry.
3. Press the tape down firmly with a roller.

Avoid

• PTFE-coated fabric. Treat it as PTFE.

Poor for a lasting bond. The adhesive can grip paper, but the bond is only as strong as the paper’s own fibres.

What decides the bond

Dow lists paper as a silicone adhesive surface, but peeling tears the fibres rather than the adhesive. Open felt and cork give only partial contact, and there is no published tape data for them.

How to prepare it

1. Seal the surface if the bond has to last.
2. Otherwise accept a bond no stronger than the material, and trial it first.

Avoid

• Relying on it where a lifted tape would cause a problem.

Trial it first: press a short strip onto the real surface, leave it a day (and put it through a heat cycle if it will run hot), then peel it. Firm, even resistance with nothing left behind is a pass. An easy, clean release, or paint, fibres or coating coming away with the tape, is a fail.