rte203

US composites told me the same thing, they said I needed to use 1708, but from what I've read and heard on here, I don't agree. I did notice when I glassed the inside of the stringers where the motor mount bolts thru, the glass was very easy to distort.
I did however find what I hope to be a good deal on the 17oz 45/45 glass at infinity composite, purchase a 67 yard/ 100lb roll for 285.00, which works out to 4.25 per yard. Any tip on the best ways not to distort when wetting out?

Glassic R.T.

RTE 203 , this is just an Example : 1708 is a very common biaxial . 17 being the weight of the fabric in ounces which is two layers of glass ( fabric ) and the 08 means a third layer of glass or mat / CSM , which means these mats have a binder designed for polyester resins that are often used with Epoxy resins with satisfactory results ( Which Are Not Recommended To be used with Epoxy resins ) because ..................................the binder may cause clouding and prevent thorugh wet out which in the long run means you will need to use more resin then normal .

Glassic R.T.

RTE 203 ,just a quick mention , and that is ...........................the purchase that you made from infinity Composites ( fabric ) is a very good price at $ 4.25 a yard , and the best advice i can give you on wetting out this fabric is .................. do not try to wet the fabric out prior to layup which means have everything ready to rock , pre cut ,set in place , wet out accordingly , and trim where needed .

rte203

Someone told me , I forget who said I should wet the plywood with epoxy , wait about 45 mins so it's sticky, then place the glass and wet it. I didn't coat the outside of the stringers, I did coat the inside before I capped them, I think I will have to put a coat on the plywood firsts then lay the fabric, right????

glassdave

iTrader: (1)

Most of the supply houses say you can use 1708 because for a while its all they carried. It can by used but you are far far better off with a matless bi-ax. Technically any mat in an epoxy layup will be a weak link even though there are epoxy compatible binders these days plus they are a pain to wet out. If you do use 1708 you should probably lay it with the mat side up/out to give at least the first layer the advantage of a good clean bond at the base of the stack of laminates.

There are a few ways you can wet out 1700 and minimize distortion (elongation). The reason they distort is usually a result of patterns being cut with the binding threads going cross the short axis of a given shape. On long rectangle shapes like the ones you will probably be using the stitching threads will run the length and hold the piece together better. Elongation is what makes it tough and working with that thread direction will go in your favor. An example of a tough shape would be if you tried to cut short 6" wide tabbing strips along the width of the roll, they would be almost impossible to wet out and apply as the threads would only keep the width in check and the length would be free to move like one of the Chinese finger trap kids toys. Its best to cut the patterns just prior to use and try not to move them around to much.

Using 1700 will make the wet out process much easier on large flat work like what you are doing. Cut your first patterns and carefully dry fit then cut the rest using this as a template, pre wet the surface then fit the first pattern. I use those six inch wide small pink rollers from Home Depot to apply resin, great. After the laminate is saturated use a yellow bondo spreader to pull out excess resin and balance it. One of the biggest mistakes i see on the do it youselfer level is overly wet saturated laminates. To much resin will weaken the pile and make it difficult to work with. A good balance helps keep its shape and ability to cling properly to surfaces. Work with slow resins and keep an eye on it as it sets up, epoxy has a tenancy to slowly creep/drift and can walk itself out of a laminate sometimes. Another trick is to mix in flat shallow pans, epoxy in mas can heat up and take off if your not careful or fast enough.

Good luck

Glassic R.T.

RTE 203 , when doing your layup might i suggest staggering your fabric from big to bigger thus making your foot print or sole bigger with each piece of fabric giving your repair more structural integrity or strength .

rte203

Hey Dave, is surfacing veil what use after the 1700 to make the area in the bildge smooth?

rte203

Thanks for the tip glassic, I will plan for the overlap you suggest.

glassdave

iTrader: (1)

As long as the binder in the veil is epoxy compatible you can use it. Hour for hour though i have found it just as easy to trowel out a surface fairing compound like Adtechs final fair or something like that. You can also use a fine finishing cloth or one of RT's cheese cloths

Theo49306

The new 1708 from Vectorply EBXM1708 will work with Epoxy, this does not have a chopmat attached, it is made by chopping gun roving and then stiching while the 45's are made, the older 1708's were made with mat. You can still get the bindered 1708, made in China called EBXM1708C. Use a rubber squeegy when wetting out the 1708, dont push too hard, rollers will pick up the stiching. Also place masking tape where you want to cut the glass, this will help keep the layers from coming apart, pull tape before the resin cures.