Proper way to repair a break to a circuit board?

[Leonc]

Thanks to Fedex, vibrato board on my Magnatone M13 got the corner broken. So the question is...what is the proper "glue" to repair this with?

http://www.patchWerkz.com/LeonsGear/MagnatoneM13/M13guts_6.JPG

[Trout]

Is that actually a PCB board? or just an eyelet board?

If it is just an eyelet board,

That old phenolic material is terrible to try to glue. I have had ok results clamping the break closed and wicking in ulta thin cyanoacrylate*. It is important the joint is pressed closed BEFORE applying the adhesive.

Note, the joint will not be especially strong, but as long as you are not dealing with any PCB traces it should be fine.
Looking at the picture of the break, you could just leave it.

* thin penetrating formula from the hobby store.

[Leonc]

Thanks for your help - not a PCB board; it's an eyelet board. May be made of fiberglass. Maybe just some epoxy...?

[Rosewood]

I would glue up the crack first with something like super glue with catalyst or epoxy and if it needs to be stronger sand area around the crack and lay fiberglass cloth and epoxy or thick super glue with catalyst and the cloth over the crack. It may be that just gluing the crack is enough if no pressure is put on that area.

[trisonic]

I'd go with Epoxy and glass, Leon.

Best, Pete.

[Trout]

Epoxy will not bond to that Phenolic material, It peels right off unless a lot of tooth is sanded into the surface.

ulta thin cyanoacrylate ( super glue ) will bond a good joint, but only in a limited capacity, the catalyst (kicker) will speed up curing.

Heck,
in his case, a bit of ge silicon rubbed into the crack might be the simple solution those things really do not support a load or anything.
Could just even leave it that way.

[kidmandude]

proper way is to replace the board!

[teletroy]

I would just break it off all the way and drill a hole and put in a new eyelet and solder that cap wire and resistor to it. Of course I'm assuming since I can't see the back side that something isn't in the other two eyelets :)

Guess you could always mount a tag strip to the board and just move the parts there.

[jbltwin1]

I've had pretty good luck with a fleixble epoxy from rubberseal that seems to bond pretty good. What I do though, is drill 1/8" holes, maybe two of them wide, on each side of the break. Then, scuff up the board with 80 grit nd epoxy. The holes aloow the epoxy to go through and grip kind of from behind and leave a little hanging out the bottom, like and anchor. Got the idea from how we fix rubber car bumpers. Gives a lot more gluing area.

[fizbin]

What material exists that JB Weld cannot fix?

I've had waaay better results with it than with Super Glue or Gorilla Glue, especially where there is minimal bonding surface area.

[Structo]

I would just super glue it and call it good.
It isn't anything that will effect it electrically.

[Leonc]

Thanks all, used a wee bit of epoxy; worked like a charm.

[davemccarthy707]

DO NOT SAND PHENOLIC!!!!! It has been banned from aircraft use for a while, because of the chemicals contained in it (one of which is formaldahyde).

[Trout]

DO NOT SAND PHENOLIC!!!!! It has been banned from aircraft use for a while, because of the chemicals contained in it (one of which is formaldahyde).

There is formaldahyde in 90% of the homes in the USA.

Sources of formaldehyde in the home include building materials, smoking, household products, and the use of un-vented, fuel-burning appliances, like gas stoves or kerosene space heaters. Formaldehyde, by itself or in combination with other chemicals, serves a number of purposes in manufactured products. For example, it is used to add permanent-press qualities to clothing and draperies, as a component of glues and adhesives, and as a preservative in some paints and coating products.

In homes, the most significant sources of formaldehyde are likely to be pressed wood products made using adhesives that contain urea-formaldehyde (UF) resins.

Pressed wood products made for indoor use include: particleboard (used as sub-flooring and shelving and in cabinetry and furniture); hardwood plywood paneling (used for decorative wall covering and used in cabinets and furniture); and medium density fiberboard (used for drawer fronts, cabinets, and furniture tops).
Medium density fiberboard contains a higher resin-to-wood ratio than any other UF pressed wood product and is generally recognized as being the highest formaldehyde-emitting pressed wood product.

Other pressed wood products, such as softwood plywood and flake or oriented strand board, are produced for exterior construction use and contain the dark, or red/black-colored phenol-formaldehyde (PF) resin. Although formaldehyde is present in both types of resins, pressed woods that contain PF resin generally emit formaldehyde at considerably lower rates than those containing UF resin.

You could not produce enough formaldahyde sanding that tiny crack to be of any significant hazard.
If anyone is seriously worried about formaldahyde exposure, IKEA would be next best thing to a gas chamber.

[Eagle1]

If anyone is seriously worried about formaldahyde exposure, IKEA would be next best thing to a gas chamber.
:rotflmaoThat made me nearly spit tea on me laptop.

[Baxtercat]

pre-CBS formaldehyde is stronger than the new stuff.

[alberob]

Leon,. if you need to increase the strength I have used small pieces of wood cut to traverse the cracks with epoxy.I cut them from an ice cream stick ,not pretty but very secure

[jbltwin1]

Pre-cbs is only stronger if it's biased properly.