Building a Kit with CA Glue

[Kyle_Y]

Hey Everyone-

   I've tried my hand at some kits (Accurail, and Athearn Blue Box). They're nothing overly complicated, but much more gratifying than RTR I think. However, I'm kind of lost as to what glue to use. I currently have been using a bottle of "Thin" CA on my cars. I like it's grip, and quick set time. However, it's super thin, and well messy. It also left a white, crusty looking residue on a recently completed kit. Is this too much glue? I'd like to find a product with similar bonding qualities, but maybe a little more viscous. What do you guys recommend?

 

Kyle

[Anonymous]

I cannot recommend the use of thin CA for the assembly of plastic kits. It is too thin and "runny". You can use either CA gel or any ordinary plastic cement.

[doctorwayne]

I use lacquer thinner as a cement for all styrene kits.  Apply it with a brush sized to suit the job.  Scrape or file any paint from mating surfaces.  You can apply a little thinner to both surfaces, then join them, or you can assemble the two parts, then apply the thinner to the joint.  It dries quickly, although allow overnight drying for maximum strength.

It's economical enough for big jobs...

 

...and works well for small ones, too:

 

Wayne

 

[doctorwayne]

I find that it's very similar to Testors Liquid Cement for Plastics, except it's a whole lot cheaper.  I buy it by the gallon, as it's also useful for thinning lacquer-based paints, cleaning brushes, etc.  I decant it into smaller cans for the various end uses, and for small projects like that crossing shanty, into an old Testors cement bottle with the brush-in-the-cap.  Exercise the usual precautions for such solvents.

 

Wayne

 

 

[G Paine]

If you use Testors Liquid Cement, the first things to do is throw away the brush stick in the cap. It is way too big for applying the glue without gobbing it all over the adjoining surfaces. Get an inexpensive small artists paintbrush and use it only for gluing.

[bogp40]

Laquer thinner, MEK and the Liquid Testors requires a small brush and good technique in applying as it dries very quickly. It has it's uses and does provide a superior bond. I tend to use it when cementing larger pieces of styrene or for backing up any sort of reinforcments to a shell or structure.

Testor's Model Master and my favorite, Faller Xpert have the needle applicator and can be placed w/ precision, eliminating excess oozing from the joint. The consistancy of these glues allows time to reposition and will produce a very good penetrating bond.

I will use CA for cementing any dissimilar materials. Metal to plastic, Delrin to plastic or metal etc Even wood to metal or plastic) One thing to note about CA, the bond is brittle. and shouldn't be used for any stress joints. The fumes will craze clear plastic as well. So remove any glazing before Caing those detail parts on your prized shell.

[dstarr]

For plastic kits you want to use a "plastic welder" cement.  There are three of four brand names.  It comes in bottles with a brush in the cap, it's water white.  The stuff softens the plastic, the softened plastic sticks together.  Then the cement evaporates and the plastic hardens.  It will make a joint as strong as the original plastic.   It's thin enough to suck up into joints by capillary action.  It evaporates completely so minor slops of cement will dry off and not leave marks.   It only bonds plastic, it doesn't stick to anything else.  

   Chemically the stuff is the same as lacquer thinner or MEK, both of which can be purchased at hardware stores in quart cans.  A quart of lacquer thinner costs about the same as a 2 ounce bottle of "cement" from the hobby shop.

[tbdanny]

Kyle_Y

It also left a white, crusty looking residue on a recently completed kit.

Kyle,

I've used CA for most of my kits without any problems.  The trick is to use a small bit of wire (such as a straightened-out paperclip or sewing pin) to spread it, and to do so thinly.  Also, keep a bottle of nail polish remover handy.  The cheaper ones are mostly acetone, and it's the acetone that dissolves CA.

As for the white finish, that is a sign of too much glue, but it can be easily fixed.  Dipping the affected parts in a bath of the previously-mentioned acetone-based nail polish remover should do the trick.  At least, it's worked for me.

Hope this helps,

tbdanny

[dstarr]

For plastic kits you want to use a "plastic welder" cement.  There are three of four brand names.  It comes in bottles with a brush in the cap, it's water white.  The stuff softens the plastic, the softened plastic sticks together.  Then the cement evaporates and the plastic hardens.  It will make a joint as strong as the original plastic.   It's thin enough to suck up into joints by capillary action.  It evaporates completely so minor slops of cement will dry off and not leave marks.   It only bonds plastic, it doesn't stick to anything else.  

   Chemically the stuff is the same as lacquer thinner or MEK, both of which can be purchased at hardware stores in quart cans.  A quart of lacquer thinner costs about the same as a 2 ounce bottle of "cement" from the hobby shop.

[modelmaker51]

I would stay away from the plastic tube cements, those are for kids who don't mind glue oozing out from the joints. Either use one of the liquid cements or MEK as others have mentioned. I'm not a big fan of using laquer thinner, for me it doesn't seem to penetrate deep enough for permanent bond, I've had joins pop apart on me where I have used laquer thinner. With liquid cements, you have to bring the parts together and then flow the liquid into the joint from a brush. If you try to apply the cement first, it will evaporate before you can bring the parts together.

CA adhesives come in for varieties, thin, medium, thick and gel. I don't like the gel for the same reason as I don't care for tube cements - too much ooze. For most CA applications I use the medium, it's much easier to control and also gives you a few extra seconds to make adjustments. Never apply CA straight from the bottle. Use a bottle cap to pour off a few drops and use a piece of wire (about the thickness of an Athearn handrail) or a toothpick, etc., to pick up a drop and apply to the joint. With CA, less is better. While you may not find the medium CA at hardware stores, most hobby shops do carry it, whether it's MR or RC.

When assembling buildings, put two walls together, add a small drop of CA at the bottom and top corners to "tack" the corners in place, then apply the plastic cement (MEK) to the whole joint for a permanent bond.

[Kyle_Y]

I picked up some "Thick" CA from my favorite hobby shop on the way home from base tonight. I put together another section of 5 car string of wells. The difference is ten fold. I ordered some precision glue tips, since my LHS didn't have them. I reduced the swear words, and crazing by 100%. Thanks guys.

Kyle

[ChadLRyan]

Say, I went on a trip to LaCrosse, WI & their Hobby shop today.

I picked up the black (rubbery) & 'Insta-Flex'  CA's today.  

I have not tried them yet, but my challenge is to install wire cut bars to a loco that stick out a bit & present a masking issue for painting. Normally this doesn't work out well for me, so I will post my results when I try these out. (I also use the toothpick & wire technique, Jay just mentioned, it works!)

Have any of you tried these CA's?  Please share your experiernces, thoughts, & opinions on these.

Thanks, 

[alanprocter]

I have used the tube testors for many structures but use VERY little - pick up a dab with a tooth pick.  I like that you have a few seconds or more to exactly position the parts.  I will also use a solvent to mate difficult parts that are small or require some "english" to push them into place.  In this latter category, I use Tanex 7R frequently - it is fast and has good "grab."  This solvent is methylene chloride, is very volatile and is quite aggressive on plastic but it does produce an outstandingly strong bond.  I am currently building a 1/350 scale warship and these have many very small and detailed parts.  I am using CA glue for many of these joints - either the medium or the gel.  As others have said you just use a micro amount.  My technique is to put drip on a piece of masking tape stuck to some scap wood using a dropper for the meduim or squeezing a small drop from the gel tube.  I then use a needle in a holder to apply the small amount to the part and put the part in place - usually with tweezers.  The CA has good "grab" to hold it for a few seconds, then i apply a small amount of CA accelerator solvent - this instantly "freezes" the bond securely.  You need very little of the accelerator, I just touch the bond area with a microbrush that has been dipped in the accelerator.  You can mop up any excess accelerator with a cotton "Q-Tip."

Hope this helps.

Alan

[Medina1128]

I've used MEK (methyl ethyl ketone) for a couple of years. It bonds the joint the same way that liquid model cements do, and it's a lot cheaper. For what a small bottle of Testors costs, I can buy a quart can. Make sure you use it in a well ventilated area.

[JohnReid]

I build a lot with wood but will use CA on occasion to tack things together,I work in a well-ventilated area but still don't take a chance as I seem to have developed a allergy to it.

[Doughless]

For structures, I use small drops of CA gel and small drops of tube plastic cement, alternating them down the length of the wall.  The CA provides a quick bond to tack the pieces together and the welding glue helps to form a better long term bond than the CA, IMO. 

I haven't built a rolling stock kit in a while, but I believe that I used so little glue, it didn't matter if it was CA or plastic welder glue.  My Accurail and old MDC kits tend to press fit together, IIRC.

CA can become brittle and if I used too little of it, without the welding glue, the pieces could pop off when handled too much.