Questions & Answers – Sealants & Adhesives
As a specialist distributor, we like to think we can offer some assistance by way of questions & answers to sealants & adhesives queries.
We often encounter similar general enquiries & queries, some more technical than others, but we’ve gathered a handful of these and presented them in a handy blog format.
Production line builders merchants – or the ‘sheds’ as they’re known – tend to prioritise sales rather than customer enquiries and technical information. Using our knowledge and experience, we strive to provide a useful and slick customer service, with a heavy focus on ‘going the extra mile’ regarding sealant and adhesive product selection.
We like to think it’s these unique selling points that give us an advantage when dealing with transactions from enquiries to sales and aftercare.
If you have any questions at all, you’ll find that our capable technical sales team can answer most frequently asked questions quickly and easily either:
- one to one in the showroom (google maps)
- over the telephone (020 8524 1931)
- via email info@county.construction
As well as this Questions & Answers – Sealants & Adhesives blog post, we also have an ever-growing list of other, useful various blogs available, to assist our customers in their daily jobs & projects. For even more help, useful information and advice check out our list of blogs here.
Sealant Finishing/Tooling Off
Q: How do I get a nice finish to my sealant bead after I’ve gunned it out?
Α: You might’ve seen a professional do it or else just noticed the fact that a cured, finished bead of sealant looks neat and tidy. This is achieved by what’s known as ‘tooling off’.
There’s a few different ways to do this, but all involve a some sort of smoothing action.
The most important thing to remember, whatever method you use or whichever material you’re using, whether it be silicone, polyurethane or polymer of some sort, you must use a barrier so that your chosen tool will not stick and/or drag the applied sealant in the joint. This is done by spraying the joint and tool with a soapy liquid such as a dedicated tooling solution (or, as used by many professionals, a mix of washing up liquid & water.) Then, with a specific tool suited to the joint size, such as a plastic block, shaped stick or even a finger is then moved slowly but surely over the bead to give the desired finish. Any excess residue can be carefully scraped from the surface to leave a smooth line of sealant prior to curing.
Recommended products:
- Skeleton Gun
- Smoothing Agent Liquid
- Marble Smoothing Liquid
- Cleaning Wipes
- Fugi Profiling Kit
- Angled Tooling Set (Squared)
- Angled Tooling Set (Rounded)
- Wave Tooling Sticks
- Palu Tooling Block
- HD Spray Bottle
A full list of mastic joint sealant smoothing, tooling and finishing tools & equipment can be found on our E-Shop here.
Choosing A Product For External Windows
Q: There’s so many different sealants, it’s really confusing! What should I use for around a window frame on the outside?
Α: Whilst there’s a few different options for this type of application. The first thing we need to decide is whether it needs to be painted over, either now or in the future?
If so, then the best choice would be to use a hybrid polymer sealant that can be painted over when cured and indeed in the future.
If it won’t need painting over now and you’re sure it won’t need painting over in the future, then the best choice would be to use a good quality Low Modulus silicone sealant such as 3C LMT Dowsil C60 or Everbuild 825.
As an example of this, for UPVC windows, in general, although they can be painted, there’s less chance of wanting to coat this material in the future, so, using LMT in either a white, or another common stock colour to match the other substrate whether it be stone, brickwork, blockwork etc. would be the BEST choice.
Recommended products:
- Skeleton Gun
- Professional Gun
- 3C LMT (Low Mod Trade) Silicone
- 3C Polymer Sealant
- Cleaning Wipes
- Dowsil C60
- Everbuild 825
- Wave Tooling Sticks
- Palu Tooling Block
- HD Spray Bottle
A full list of external mastic joint sealants can be found on our E-Shop here.
Fixing A To A Wall Using Adhesives
Q: How can I put a mirror up on my wall without using fixings?
Α:We get asked this question a lot and we always give the same answer. A common misconception is that, whilst most silicone’s have a degree of adhesive properties, many mirrors have foil backing on the glass that isn’t compatible with the chemical ingredients used in silicones (especially acetoxy) and so the correct choice in most cases would be a dedicated mirror adhesive of which there are several available on the market and do a fair job of sticking smaller, lighter mirrors on walls, but we prefer the overall final bond strength of 3C Max-Bond to do a proper job first time and give you some peace of mind that the adhesion will last the distance.
Recommended products:
- Skeleton Gun
- Tajima Dual Power Gun
- 3C Max-Bond
- Cleaning Wipes
- Dowsil 817 Mirror Adhesive
- Everflex Mirror Mate
- Hodgsons Mirror Adhesive
A full list of mirror adhesives can be found on our E-Shop here. / A full list of power adhesives can be found on our E-Shop here.
Preventing Mould Growth On Sealants
Q: How can I prevent mould growth on the silicone around my bath & shower etc. in my bathroom?
Α:This a tough one but can be explained with one important word… ‘ventilation’! Regardless of the products used, the way they’re applied and the aftercare, the key factor in the prevention of mould growth on cured silicone sealants in any areas of high humidity is adequate ventilation.
Of course, extractor fans are installed as standard in bathrooms these days where necessary, due to regulations, (especially in new builds) and they do a decent job of taking some steam away after a hot shower etc.but an upgrade often conjures up images of expensive devices such as dehumidifiers and premium extraction fans. This needn’t be the case, the easiest and most cost effective way of airing a room is simply opening the window during and/or after use. The other top tip for helping your silicone sealant to stay mould-free is to rinse it down with clean water and dry it as best as possible also. If you’re actually renewing or starting from scratch then considering using a high quality silicone sealant with fungicide such as 3C HM is a very good start.
Recommended products:
- Skeleton Gun
- Professional Gun
- 3C HM Sanitary Silicone
- 3C Multi-Use Adhesive & Sealant
- Cleaning Wipes
- BT1 Ultimate
- Everflex Forever White
- Hodgsons U7N
- Ottoseal S100
A full list of anti-mould mastic joint sealants can be found on our E-Shop here.
Protection Of Surfaces & Edges
Q: Can I fix protection onto surfaces to help with wear & tear?
Α:A great way to add some quick & easy protection to either; flat areas (such as concrete ramps or storage containers etc.) or frame edges (such as corners of doorways & furniture etc.) is to use solid steel or aluminium plating. There’s various types on the market from flat to patterned, but one we love to use as it’s so robust, reliable and gives the best overall decorative look is checkerplate. It comes in many different thicknesses and will protect wood, plastic, metal, concrete, stone and many more surfaces from erosion, accidental
damage and general scuffs etc. without the risk of rusting.
Now, how do we mount this material onto the materials mentioned above? Well, of course, with the correct tools, you can drill holes and use screws to fix the protection into place but this doesn’t always look good so we prefer the more aesthetic approach of using glue such as our 3C Max-Bond to stick the plate or edge down. Depending on the surface area of the protective sheets and/or edging, it doesn’t require an awful lot of product and it’s an effective method of joining with great initial grab and un-matched final bond strength.
Recommended products:
A full list of power adhesives can be found on our E-Shop here.
Removing Old Mastic Sealants From Joints
Q: How do I remove old mastic sealant?
Α: There’s a few products and tools available on the market especially made for removing old sealants such as silicone and some of these are useful but what the professionals prefer is a good old fashioned sharp blade and some elbow grease.Usually the sealant has adhered to 2 x sides and needs to be de-bonded from both surfaces to be fully
removed. This is done by carefully pushing the blade close to the bonded surface and pulling along the bead to effectively cut the cured product all along the line, this is then repeated from the other angle, again, as flat as possible to the surface and pulled along the bead. Once both sides have been cut, the whole bead should come out as a rubber snake (or at least in some decent lengths) The residue can then be scraped and wiped and/or brushed off to make both sides/surfaces clean and tidy, ready to receive a new bead.
Recommended products:
- Silicone Eater
- Cleaning Wipes
- Silicone Sealant Digester
- Strip Out Tool
- Safety Scraper
- Stainex Degreasing Paste
- Titan knife
- Twistknot Wire Brush
A full list of mastic joint sealant removal tools & equipment can be found on our E-Shop here.
Applying Mastic Joint Sealants In Different Weather Conditions
Q: Does the weather matter when it comes to applying sealants outside?
Α:This question is asked frequently by DIY users and professionals alike with the majority of people wanting to know either; the lowest acceptable temperature or if there’s a product(s) that can be used in damp or wet conditions, so we’ll try to address these particular ones.
As mentioned in a previous question, choosing the correct product for an external application should be the first priority but obviously another consideration is to assess the surface and weather conditions in which you’ll be applying the product.If the outside temperature is anywhere between +5° to +40° C then most low modulus silicones, polymers, hybrid polymers will be perfectly fine to use, providing the surface is completely dry. If it’s below 5° then ground frost is usually the biggest issue as well as the curing system struggling.
If one (or both) of the substrates is wet or even damp and manually drying isn’t possible then careful attention and caution should be used and silicones completely avoided as this material wont cure efficiently and is likely to fail in adhesion. If the surface(s) are wet then application is possible using a polymer sealant (such as 3C Polymer) or a hybrid polymer-based sealant (such as 3C Multi-Use) but even then, some form of manual drying should be done to a satisfactory level that one would then consider the area as damp (as opposed to wet) Please note these types of products are quite forgiving but doing a small test area prior to full use is always advised to assess adhesion
Recommended products:
- Skeleton Gun
- Professional Gun
- 3C Multi-Use Adhesive & Sealant
- 3C Polymer Sealant
- Cleaning Wipes
- Everflex Weather Mate
A full list of damp/wet tolerant mastic joint sealants can be found on our E-Shop here.
Choosing Which Type Of Adhesive Glue To Use
Q: What’s the difference between all the adhesives available?
Α: As there’s many different adhesives (or glues) on the market, that come in all shapes and sizes, we’ll stick to the cartridge-based ones for this question. When it comes to bonding 2 x similar or dissimilar materials together or fixing one material to an existing substrate, then there’s really 3 x types of products that can be used, so deciding on the best for your application can be important.
The first is the generic ‘grab’ or ‘grip adhesive’ which has been around for decades and took care of many tasks where light to medium bonding was required, however, although you can still get some of these in hardware shops, the harsh chemicals used in these types of products are fast becoming outlawed in every country with health & safety considerations forcing a re-think of materials.
The second is the ‘multiple use’ products that are essentially designed to be a sealant & adhesive all-in one. These have become a very popular choice for various tradespersons and DIY’ers due to the fact they can carry a single item that can stick and seal on many surfaces and in many situations. If you’re after a decent glue for light duties around the home, then a product such as 3C Multi-Use is perfect. The only drawback with the ‘all-in-ones’ is that, as an adhesive they can do a good job for light to medium fixing
applications but fall short of a perfect final bond for anything a bit meatier (such as over 2.5kg on verticals)
Enter the third type of adhesive. Power adhesives such as 3C Max-Bond! These type of products are designed to be far better suited to heavier tasks and exhibit extremely powerful final bond strength when fully cured. As well as having this superior staying power, these products often have excellent grab or grip properties as an added bonus making them a solid choice when an application is such that manoeuvring heavier items into exact place is an issue (although providing full support during the curing process is always strongly advised). As most power adhesives such as Max-Bond are hybrid polymer-based, they are slightly damp tolerant which is handy if using externally in poor weather conditions as they are much more forgiving to moisture when applied.
Recommended products:
A full list of all our adhesives can be found on our E-Shop here.
Preventing Mould Growth On Sealants
Q: Why does sealant crack, like the stuff around my coving & skirting boards?
Α: This is a very simple question to answer because they’re nearly always water-based products! The traditional caulk (or caulking) is generally a filler made up of acrylic and water which inevitably evaporates after curing, then shrinks in all directions causing the bead to crack, split and break over time (sometimes not a very long time at all ☹) It’s an all-too-common sight to see above skirting boards, around door frames and also at the top and bottom of ceiling covings whether you painted it yourself or even if a professional tradesperson like a painter & decorator did it.
Like all construction materials, the technology moves on and nowadays, although there’s still cheap and cheerful decorators caulks and fillers available which will do a decent job (some are better quality then others) there’s also newer options such as siliconized caulk and polymer-based sealants such as 3C Polymer which does an excellent job of gap filling and then takes paint over the top perfectly well for a long-lasting seal, this is because it has better elasticity and will accommodate movement much more efficiently than water-based acrylic sealants.
Recommended products:
- Skeleton Gun
- Professional Gun
- 3C HM Sanitary Silicone
- 3C Multi-Use Adhesive & Sealant
- Cleaning Wipes
- Caulk Once
- 3C Paintable
- Paracryl Transparent
A full list of premium caulk mastic joint sealants can be found on our E-Shop here.
What Sealant To Use For General Sealing
Q: I’m not very handy but just need a basic sealant for sealing a couple of things around the house mainly inside and the odd outside job, what should I use?
Α: There is a category of sealants known as General Purpose (or simply GP sealants) made exactly for this purpose to cut through the gumpf and provide a product that seals gaps for little jobs.A good rule of thumb if you’re not well versed in the many different types of sealants is to buy a silicone-based GP sealant that has anti-mould fungicide in, such as our 3C GP Silicone, that way you can use this product to seal all around the house including the kitchen, bathroom and even do some light outside sealing jobs without worrying if it’s the right product.
Recommended products:
A full list of general purpose sealant products can be found on our E-Shop here.
