The earliest bushing designs use electro porcelain for both indoor and outdoor applications. Porcelain is impervious to moisture once sealed by fired glaze and is low cost and flexible to manufacture.
The main disadvantage with porcelain is that its small value of linear expansion has to be accommodated by using flexible seals and substantial metal fittings, both of which present manufacturing and operational problems. A basic porcelain bushing is a hollow porcelain shape that fits through a hole in a wall or metal case, allowing a conductor to pass through its center, and connect at both ends to other equipment. Bushings of this type are often made of wet-process fired porcelain, which is then glazed.
A semi-conducting glaze may be used to assist in equalizing the electrical potential gradient along the length of the bushing. The inside of the porcelain bushing is often filled with oil to provide additional insulation and bushings of this construction are widely used up to 36 KV where higher partial discharges are permitted. Where partial discharge is required to conform to IEC, paper and resin insulated conductors are used in conjunction with porcelain, for unheated indoor and outdoor applications.
The use of resin polymer, polymeric, composite insulated bushings for high voltage applications is common, although most high-voltage bushings are usually made of resin impregnated paper insulation around the conductor with porcelain or polymer weather sheds, for the outdoor end and occasionally for the indoor end. Another early form of insulation was paper, however, paper is hygroscopic and absorbs moisture which is detrimental and is disadvantaged by the inflexible linear designs.
Cast resin technology, has dominated insulated products since the s, due to its flexibility of shape and its higher dielectrical strength. Typically, paper insulation is later impregnated either with oil historically , or more commonly today with resin. SRBP insulated bushings are typically used up to voltages around However, above 12 kV, there is a need to control the external electrical field and to even out the internal energy storage which marginalises the dielectric strength of paper insulation.
To improve the performance of paper insulated bushings, metallic foils can be inserted during the winding process. These act to stabilize the generated electrical fields, homogenising the internal energy using the effect of capacitance. The condenser bushing is made by inserting very fine layers of metallic foil into the paper during the winding process. The inserted conductive foils produce a capacitive effect which dissipates the electrical energy more evenly throughout the insulated paper and reduces the electric field stress between the energised conductor and any earthed material.
Condenser bushings produce electric stress fields which are significantly less potent around the fixing flange than designs without foils and, when used in conjunction with resin impregnation, produce bushings which can be used at service voltages over one million with great success.
Since the s, resin materials have been used for all types of bushing up to the highest voltages. The flexibility of using a castable form of insulation has replaced paper insulation in many product areas and dominates the existing insulated bushing market. As with paper insulation, the control of electric stress fields remains important. Resin insulation has greater dielectric strength than paper and requires less stress control at voltages below 25 kV.
What is the difference between poly resin and epoxy resin? Which is best for filling voids in wood? Poly resin is very similar to epoxy resin, but is generally less flexible once cured.
Epoxy cures harder than poly, and is therefore more resistant to scratches. Not Helpful 10 Helpful Not Helpful 0 Helpful 1. How do you and color and patterns and can you drill holes into it? Answer this question Flag as Include your email address to get a message when this question is answered.
Already answered Not a question Bad question Other. Tips Curve any corners if you are able, as it is difficult to work fiberglass mat around sharp corners. Temperature affects the speed of hardening of the polyester resin, as does the amount of hardener used. To ensure an even impregnation of resin to the cloth, try sandwiching the cloth between two larger sheets of clear plastic sheeting.
Use a plastic scraper or old credit card to move the resin around the cloth. You can also trim your impregnated cloth into a specific shape or size by tracing onto the plastic. This also makes clean up a lot easier Large projects can be built by forming separate sections and then fiberglassing each one, then using fiberglass and resin to join them together.
Warnings Wear gloves and safety glasses when applying the resin, and avoid contact with skin. Do this project in a very well ventilated area. Polyester fiberglass resin produces significant heat when catalyzed, especially if too much hardener is used. Things You'll Need Enough Fiberglass mesh to cover what you want it to do. Did you try these steps? Upload a picture for other readers to see.
Tell us more about it? Click here to share your story. Working with Glass In other languages: Werken met glasvezelversterkte kunststof Print Edit Send fan mail to authors. Thanks to all authors for creating a page that has been read , times. Did this article help you?
I used waterproofing tape applied from the inside where possible to help build a surface for large holes. MD Mohammed Dirar Nov 23, Polyester fiberglass resin produces significant heat when catalyzed, especially if too much hardened.
LV Louis Valez May 19, But, after reading your website guidance I successfully utilized fiberglass for transom replacement. NB Nancy Brault Aug 17, Thanks for building my confidence to try this process on my own. CP Clay Peterson Apr 5, It's been a while since I've used the fiberglass mats, and I needed a refresher course on strand orientation. JJ Jennifer Jones Mar 22, I am completely new to the concept of fiberglass molding and this gives me a good place to start experimenting.
SA Scott Anderson Sep 16, Always makes it easier to understand. CB Carlos Blair Jan 17, JC Jose Chairez Jun 7, CC Colin Chamberlain Oct 25, VS Vince Silva May 16, What a great idea to decorate a special gift with a creative flair!
Get the tutorial via craftandcreativity. Feed old book pages through a printer to make fun and fabulous silhouette art. Get the tutorial via rufflesandstuff. What a cute spring or Easter decorating idea. And easy to make. Get the tutorial via homemademodern. Use your old sheet music books to create these Christmas trees that are sitting on tart tins and add to vintage charm. What a great idea! Get the tutorial via layercake. Try with music sheets or old book pages for a vintage affair!
Light a candle inside at night, and the music glows! Get the tutorial via belleoftheballdesigns. Assemble book spines into a stealthy box for secret storage. What a neat idea for hiding the ugly little router into a shelf.
Get the tutorial via blitsy. Letters made from rolled up book pages, pretty cool looking and simple. Get the tutorial via littlethingsbringsmiles. Make a vintage heart garland from paper — great for Valentines day. Add some cool to your home office on the cheap with this DIY project. Make this crafty jewelry with whatever favorite book text gifts for book lovers.
They also make cute gifts for book lovers. Get the tutorial via zg1. Would make a great and unique jewelry display for your space. Make 3-D paper butterflies with old book pages.
From DIY vintage book planter or recycled book paper roses bouquet to romantic music sheet covered mason jar or folded book pages cake, there ae so many cool things to do with old books! Recycled Books Resin Paper Wire Forms.
tototwo2 Resin is one of my favorite jewelry-making materials, and I especially love making forms out of wire to fill with it, like these fairy wings! Add glitter, lace, paper, just about anything that looks like *real* fairy wings ;o).
Make one special photo charms for you, compatible with your Pandora bracelets. Leaf form dancer with Ice resin. Vintage broken clay pipe part at top. Freeform Wire and Resin Jewelry: Make Angel Wings, Fairy Wings, Leaves, Flowers and More; Freeform Wire and Resin Jewelry: Make Angel Wings, Fairy Wings, Leaves, Flowers and More. February 29, She used tissue paper as a base in the wire to make hers (it literally disappears in the resin–brilliant!), but I had to experiment a bit.
Wire and resin jewelry tutorial. Posted April 24, by Katherine Swift. Dot some mixed resin into the wire forms. For this tutorial, I used Envirotex jewelry resin because I wanted a doming resin that does well when cast in thin layers. When adding in your resin, you want to dot some in using a toothpick, then use your toothpick to draw. Starlight Frames Wire & Resin by Kerry Bogert Overview - coat each side of a small piece of paper. 6) Dip your wire form in the resin and remove any dripping excess liquid. Then, lay your resin paper onto the wire frame. 7) Allow resin to cure.