A better tool for bonding BONDIC

[RBrodzinsky]

Many of you know that I tend to extol the use BONDIC as an adhesive for affixing LEDs inside loco shells. Rather than a CA or other glues / epoxies, it is a UV-cured "liquid plastic" which seals to the surfaces it is in contact with when hit with UV light.

Unfortunately, the curing lamp which comes with the kits is a bit clunky to use, so I finally decided to make my own. The first photo shows both: the upper item is the purchased BONDIC (the liquid is in the black tube), with the included lamp on the right. The light is a basic UV LED, with its leads sandwiching two 1.5V Li button batteries (for 3V total). The little orange slide switch literally pushes the lead under it down onto the battery to complete the circuit. You have to slide the orange switch back towards you, and with 1-inch batteries, it is sometimes difficult to get the apparatus and fingers into the area where you want to bond (like SMD LEDs on the inside front of an N-scale loco).

I came up with the lower item: it consists of an 0603 UV emitter (i.e. UV SMD LED), mounted at the end of a 4-inch piece of 1/8" styrene tubing. I used a small surface contact switch, in line with the ground leg of the circuit, mounted about halfway along the tube (the silver button in the blue holder. And of course, the button and the UV emitter are bonded to the tube....using BONDIC.

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This photo shows the whole unit. I put a micro connector on the far end of the wires, using shrink wrap tubing to provide strain relief both at the top of the styrene tube and at the connector. I have a 12V 500ma wall wart, with mating plug, which I use for my bench work electronics power when testing. (yes, there is a 1Kohm current-limiting resistor in line with the wire under the green shrink wrap).

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This last photo shows the emitter at the tip (have to look carefully).

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Being much lighter and much smaller, the control of the area being exposed to the UV is amazing, and much simpler and easier to use.

[jdcolombo]

Hi Rick.

Wow . . . this is a terrific idea.  I'm going to have to make one for myself.

John

[Jbub]

It reminds me of the uv curing lamps used in the dental office when they fill cavities.
Pretty awesome though. Quite ingenious.

[CRL]

Did a search & it appears Dental UV curing lights are available in Amazon for under $30.

[RBrodzinsky]

The UV emitter chip is $1 from DigiKey, the SMD resistor $0.03, and the tactile switch is $0.05 (from Electronics Goldmine https://www.goldmine-elec-products.com/prodinfo.asp?number=G22753).  Throw in wires and styrene tube.

[peteski]

Good idea on the UV light!

Rick, when I use Bondic I noticed that after it cures there is a sticky film left on its surface. Almost as if the surface is not curing, or something leaches out of the cured surface.  This occurs right after curing, and doesn't go away. I tried curing it again few times, and the surface remains moist.

[RBrodzinsky]

I’ve never seen that before. Always sets up nice and hard. Have even sanded it sometimes.

[peteski]

I’ve never seen that before. Always sets up nice and hard. Have even sanded it sometimes.

The resin is hard, but its surface is moist.  If I sand it, that will probably remove the stickiness.  I wonder if my BONDIC simply expired?

[Dredgeboater]

Hello All,

Reading the Bondic story, there is an alternative,
While being into n scale modelling as well as fly fishing and fly tying, the is an UV light cured Bond glue in the fly tying tool assortments of many (on line) shops.
The proper UV flash light can be obtained as well.
We use it as a cement to secure body material to a hook,
Thus there is no need to go to the dentist office.....

All the best,

Dredgeboater

Better to be roughly right, than to be exactly wrong.....

[peteski]

Since we are mentioning alternate UV-cred resins, here is another one: https://www.alumilite.com/store/p/1027-Alumi-UV.aspx

[Lemosteam]

Guys, just had an idea.  How thin is this stuff?, like water?  thin CA? Gel CA? Milk?

Wondering if this will absorb into FUD or FXD in a bath or dip of the stuff, then remove excess and cure.  Might make FUD or FXD much stronger because as you know they are both very porous.

Can this stuff be purchased at a store anywhere?

[woodone]

I use the Bondic glue all the time. My first problem was the battery & switch.  Switch was hard to operate & the battery died.
I took out the UV LED that came with the kit and glued it to  the end of a coffee stirrer and added a 1K resistor , put a plug on the wires leads and hooked it to a power supply- just turn it on when I am glueing Bondic .

[RBrodzinsky]

Guys, just had an idea.  How thin is this stuff?, like water?  thin CA? Gel CA? Milk?

Wondering if this will absorb into FUD or FXD in a bath or dip of the stuff, then remove excess and cure.  Might make FUD or FXD much stronger because as you know they are both very porous.

Can this stuff be purchased at a store anywhere?

More viscous than thin CA, more liquid than Gel CA.  I've use it to seal the speakers to your speaker enclosures,  but not sure if any has seeped deep into the pores.  You can get 20ml of the stuff for $16 or 50ml on Amazon https://www.amazon.com/s?k=bondic+refill  (other brands run about the same). 

I like the Bondic packaging as it provides a nice "thin" dispenser tip, but I use a toothpick to apply even smaller beads, when necessary.

Some of the other brands can be found in stores (such as WalMart).  Just look for :UV-cured liquid plastic" - RapidFix; "Liquid Plastic Welding Kit"; etc.

[carlso]

John "L",

I like your thinking here. I have used the Bondic many times as Woody and Rick and others have suggested. Personally, I do not think it would work well on the FUD or FXD if they are larger items.

However, after watching the short video about the Alumi-V product I think maybe it would work well. Not only would it strengthen the item but perhaps it would take out the pock marks and striations of FUD or FXD. It may be tricky to dip the entire item and then drain all the excess of without any air bubbles. But maybe worth fiddling with a test item. Too bad the item is not in stock right now.