In this issue of the Composite 101, 202 and Advance Newsletter:
- A composite question from a subscriber.
- How to repair a fiberglass part part-2
1. A composite question from a subscriber.
This newsletter question is from Thomas. :
How much hardener must I add to the resin when using fiberglass?
Composite 101, 202 and Advance answer:
This is one topic covered by Composite 101, 202 and Advance. As explain in the visual guide it depends of the specification of the resin some resin uses more or less catalyst. Also the kind of catalyst is important; a resin can use different kind of catalyst to influence the cure of the resin. Inside the guide you’ll find a chart to indicate you how much catalyst you need to add to the resin. The resin manufacturer indicates the percentage of catalyst has to be added to the resin to achieve the optimal cure.
When using a styrene based resin, it’s important to add the right amount of catalyst to the resin. Too much and the resin can harden too quickly and the mechanical properties of the laminate can be different than expected. Too little and the resin won’t gel or the mechanical properties can also be modify.
Generally speaking the resin to catalyst ratio is 1% to 2.5%. Adding the right amount is a part of success of making a professional quality work.
2. How to repairing a fiberglass part part-2.
In the last newsletter we saw how to prepare the surface of the part. Now we have to repair one side and then the other. You must start by repairing the fiberglass side of the part. A backing is needed to support the material. In the following example we used a 3” masking tape, because the hole is only 1.5”x1/2”. If the hole is larger you can use cardboard or a sheet of plastic, there’s a lot of solution to create an effective backing for the material.
It’s important to make sure the backing is well stick to the gelcoat so the resin won’t bleed over the gelcoat, so use your finger to press all around the hole.
For a larger hole, apply making tape on the perimeter of the hole and then use the appropriate backing.
Now it’s time to apply the fiberglass. For a small hole generally for an esthetic repair it’s simpler to use only mat. But for a larger or a structural repair you need to recreate as much as possible the same construction, if unknown then at lease the same thickness. You must fill the V you created around the hole in an earlier step. It’s important so the new material will have a good surface to bond to. Apply the material make sure there’s no air bubbles. If you have cut the material way too large, you don’t have to wet all the material only wet the portion that is used to fill the V around the hole. Sanding off dry material is easy. Now let it fully harden a minimum of 4 hours.
To be continued… in our next newsletter.
We invite you to come visit our website and take a look at the table of content
of our composite visual guide.
http://Guide.fiberglasstechnique.com
You can send us questions; simply by using the form at the top of the website at: www.fiberglasstechnique.com. Our support team will answer you and your question could be used in this newsletter and help others.
Sincerely,
__________________
Mr.Carol Fortier
Project manager
WWW.FiberglassTechnique.com |
