---------------------------------------------------------- FEWMustang-List Digest Archive --- Total Messages Posted Thu 04/29/04: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:34 PM - Re: Re: FEWMustang-List Digest: (PolymerDesign@aol.com) 2. 08:06 PM - Re: Re: FEWMustang-List Digest: (Harold Anderson) ________________________________ Message 1 _____________________________________ Time: 07:34:13 PM PST US From: PolymerDesign@aol.com Subject: Re: FEWMustang-List: RE: FEWMustang-List Digest: --> FEWMustang-List message posted by: PolymerDesign@aol.com Sorry guys I've been out of town for 6 days and just saw the questions. The advise on the acrylic glue is correct. No prep work other than having area clean. When applying the solvent less is better and be concerned with orienting the crack so gravity flows any excess solvent toward the edge where crack started. Solvent should be applied with hypodermic needle like insulin folk use. This type of repair sort of fuses the material but is not considered a weld like a crack is welded in steel. Joint strength is probably less than 25% 0f the original strength. Stop drilling is good but a special 60 degree bit MUST be used whenever drilling into Plex or Lexan. Wicks has these bits. Normal bits produce microscopic cracks or as we engineers say 'stress risers". To prevent recurrance it is important to find out what caused crack to start in first place. Most likely unless plex was scratched or had some type of notch on the edge the crack was caused by uneven mating surface. Maybe a bump or some sharp edge on the alum. or the mating part. Always use a bed of clear silicone under the plex and under any mating alum. part. You can also put clear silicone in the stop drill hole. Let canopy sit unmoved for at least 24 before handling. That's all the advise that comes to mind. I do have an extra canopy if needed. Ken ________________________________ Message 2 _____________________________________ Time: 08:06:52 PM PST US From: "Harold Anderson" Subject: RE: FEWMustang-List: RE: FEWMustang-List Digest: --> FEWMustang-List message posted by: "Harold Anderson" Ken, Thanks for the advice; you are right the crack was caused by a bump. The crack is in a non critical area of the canopy so this repair should work. As to the 60 degree bit I have drilled all the holes in the canopy using a standard bit, is this going to cause a problem further down the line? Andy -----Original Message----- From: owner-fewmustang-list-server@matronics.com [mailto:owner-fewmustang-list-server@matronics.com] On Behalf Of PolymerDesign@aol.com Subject: Re: FEWMustang-List: RE: FEWMustang-List Digest: --> FEWMustang-List message posted by: PolymerDesign@aol.com Sorry guys I've been out of town for 6 days and just saw the questions. The advise on the acrylic glue is correct. No prep work other than having area clean. When applying the solvent less is better and be concerned with orienting the crack so gravity flows any excess solvent toward the edge where crack started. Solvent should be applied with hypodermic needle like insulin folk use. This type of repair sort of fuses the material but is not considered a weld like a crack is welded in steel. Joint strength is probably less than 25% 0f the original strength. Stop drilling is good but a special 60 degree bit MUST be used whenever drilling into Plex or Lexan. Wicks has these bits. Normal bits produce microscopic cracks or as we engineers say 'stress risers". To prevent recurrance it is important to find out what caused crack to start in first place. Most likely unless plex was scratched or had some type of notch on the edge the crack was caused by uneven mating surface. Maybe a bump or some sharp edge on the alum. or the mating part. Always use a bed of clear silicone under the plex and under any mating alum. part. You can also put clear silicone in the stop drill hole. Let canopy sit unmoved for at least 24 before handling. That's all the advise that comes to mind. I do have an extra canopy if needed. Ken == == == ==