Super Glue and Sodium Bicarbonate

[Len Morris 2Participant @lenmorris2]

Just wonder if anyone has experience of using Sodium Bicarbonate powder (Baking Soda) and Super Glue with model boats.  You’re meant to pack the gap with the powder and then douse it with the glue.  Tried a couple of trials and it did seem to work well giving a hard filler that stuck and cured almost instantly.  There are lots of U-tube videos but I tend to take them with a pinch of salt.  Not seen it mentioned here before, hence the question.

Len

[ashley needhamParticipant @ashleyneedham69188]

Not heard of that one, Len.

Can’t quite see the point. Is it to glue and gap fill at the same time?

Ashley

[Len Morris 2Participant @lenmorris2]

It seems to do both Ashley.  I think there is a chemical reaction going on as it sets within seconds and the powder doesn’t seem to be just a filler.

Len

 

[Richard SimpsonParticipant @richardsimpson88330]

I’ve never been a great fan of cyanoacrylate glues.  I know I’m in a minority with that so don’t all jump down my throat!  I don’t think they stand the test of time and I think they can be a bit of a pain to use with nearly always half the bottle being thrown away because it either hardens or you can’t get the stuff out of the bottle or the cap seizes on!

I know the plastic modellers use it a lot as a filler but again, I really can’t see why.  Polystyrene glues dissolve the plastic surface and form a bond as strong as the surrounding plastic.  Cyano glues sit on the surface so I don’t see how they can be as strong.  Added to that the fumes they give off can at best be unpleasant and at worse can be dangerous and I still have one eye that itches frequently as a result of getting fumes in it.

I think a lot of stuff we see nowadays on the internet and in the like of YouTube are mainly as a result of people trying to make a name for themselves  and tend to demonstrate things that are a bit trendy rather than the best for the job.

If you think about it, if you are filing a gap in a plastic kit why wouldn’t you use a proper plastic putty that bonds with the surface or, if filling a gap in wood why wouldn’t you use a properly formulated wood filler?

Another concern I see is that cyano based fillers are invariably a lot harder than the surrounding materials hence, when you come to sand it down you invariably end up damaging the surrounding areas because they abrade easier.

Another trendy thing I see nowadays is dissolving bits of plastic sprue in liquid cement to make a filler.  I cannot begin to understand why you would faff around in such a way when you can get out a tube of Tamiya plastic putty!

Sorry, early morning moan time!  Have a good Easter guys!

[David Marks 2Participant @davidmarks2]

I use cyano (super glue) for laminating styrene sheet into a block form and also use it on wood (typically plywood) when it splits or delaminates when cutting. For laminating styrene it is to me the only suitable adhesive available and it does a good job. For the wood repair it is an instant fix. however for both styrene and wood most of my joints are with more traditional adhesives. My prefered cyano is from Toolstation (see link) and they also offer a 20g bottle for around £2.50. I always store cyano type adhesives in the fridge which helps to extend its life. For filling, I use traditional fillers, usually Isopon P38 and for little “dings” I now use the Plastic Filler marketed by Deluxe Materials.

https://www.toolstation.com/hv-super-glue/p10893

[Len Morris 2Participant @lenmorris2]

Richard, all you had to say was that you haven’t tried it and have no experience of it.  That was my question.

Len

[Richard SimpsonParticipant @richardsimpson88330]

I have tried it and I have experience of it, hence my views on the subject.  Why would you jump to the odd conclusion that I haven’t?

As I said the challenges are it doesn’t bond as well as fillers that dissolve the parent material, it’s hazardous, and it is frequently harder than the parent material so sanding it down can damage the surrounding surfaces as you try to level the filler.  That is based on experience.  Don’t ask for experiences if you don’t want them.

There are plenty of modellers with alternative experiences who swear by it so, at the end of the day, it is up to you to decide.

[Len Morris 2Participant @lenmorris2]

Richard, you mention nothing about the effect of the two combined substances, having a go at it or the results you obtained  You just talk about super glue and the alternative adhesives/fillers for plastic and wood.  What conclusions would you expect?

Len

[Richard SimpsonParticipant @richardsimpson88330]

I’ve told you about the challenges sanding it down as a result of it being frequently harder than the surrounding materials.  That is the result I obtained.

That’s three times now.

[Colin BishopModerator @colinbishop34627]

Len, I’d be interested to hear where you got the idea of using bicarb from? The usual methods of bulking out cyano to fill gaps are microballoons and talcum powder as they are both inert substances. Bicarb is very reactive which makes it useful for all sorts of things but I’d have thought that adding it to cyano might give unpredictable results. Yes, it may have gone instantly hard, but has it affected the bond to the materials it is bridging?

I don’t much like cyano myself as eventually it seems to go brittle over a few years and fittings stuck on with it fall off. I am also allergic to it, as a single whiff of the standard stuff causes severe hay fever symptoms which last for three days. I can manage the odourless variety (which really needs a kicker) and I do use this in situations where it is the best option.

I particularly like Deluxe materials Superphatic which wicks deeply into a joint and gives a really strong bond. It is also useful for bonding absorbent materials to non absorbent ones so it works pretty well with wood to plastic joints.

For wood to wood I either use Deluxe Aliphatic or alternatively Epoxy. The 5 minute variety is handy but the 15 or 30 minute types give a stronger bond.

Aliphatic and Superphatic have the great advantage of water clean up which is very useful in many situations and are easily sandable. You can plank a hull quickly using cyano, but the joint lines are harder than the material which can cause problems when sanding as Richard mentions.

There are also some interesting acrylic based single part tube adhesives such as Bostik Power Repair and UHU All Purpose Power which are handy for awkward situations with dissimilar materials.

As Richard says, liquid poly in it’s different types (they are not all the same) enables plastic joints to be literally welded together and a joint doesn’t come stronger than that but it does have a downside as I found when making the wheels for my paddle steamer. It is of course a solvent and evaporates as the joint cures. I made the mistake of using too much and the evaporation resulted in shrinkage which pulled my carefully aligned floats out of line overnight. Lesson learned.

There is nothing new about dissolving sprue and scrap plastic in liquid poly, it was used a lot back in the 70s when the specialist fillers we have today were not available.

Colin

[Len Morris 2Participant @lenmorris2]

Hi Colin,

I just saw it on the internet and thought I’d try and have a play with it.  I found that if the powder is pressed into the gap, all the excess powder is easily brushed off leaving a clean flat surface.  Because it’s just powder there’s all the time in the world to get it just how you want it.  Just an accurate drop of glue set the whole thing off rapidly.  There was no expansion of the mix and nothing to sand down afterwards.

Now to the reason for my interest.  On mi Puffer tin plate hull I had a couple of small leaks between two of the plates.  Very small gaps but now full of muck.  Trying to re-solder them wouldn’t have really worked, it would have needed major surgery.  I didn’t want to mess with the the usual fluid fillers as they take time to set and leave a surface to clean up.  I found this process worked a treat.  I’ll put some pictures on mi Puffer thread.

Len

[Colin BishopModerator @colinbishop34627]

Just did an online search and came up with this which makes interesting reading.

How Strong Is Super Glue & Baking Soda?

There are also quit a lot of other ‘hits’ on combining bicarb with cyano. It apparently sets rock hard like concrete so would be unsuitable for many modelling applications where subsequent abrading is needed.

Another string to your bow I suppose.

Colin

[Len Morris 2Participant @lenmorris2]

Thanks Colin and well found.  Just shows how the term ‘super glue’ covers no end of products and describes my experience of how it reacts with baking soda.  It does set hard which might be useful for drilling and tapping.  As you say, just something to be aware of.

Len

[Dave Smith 17Participant @davesmith17]

I’ve used it for certain applications for years on both planes and boats. It’s a good way of making a strong fillet in internal areas, but very difficult to sand down in areas where it can be seen. Sets almost instantly, generates a little heat, but gets the job done.

Very difficult to remove, so you need to be sure you’ve got the right pieces lined up exactly as they should be before you let loose with the cyano.

[Len Morris 2Participant @lenmorris2]

Very interesting Dave.  I think the hardness of a filler is just relative to the surface being filled.   Not found it a problem on metal as it’s still much softer.  One thing I did try was putting a drop of water into the baking soda to make a stiff paste to avoid dusty powder on the surfaces.  It set and glued just the same.

Len.

[Colin BishopModerator @colinbishop34627]

I think the hardness of a filler is just relative to the surface being filled.

No, I think both are absolute in terms of hardness but differ relatively to each other depending on the two materials which is not quite the same thing! (just being pedantic)

Colin

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