QuestionQUESTION: Octavio I am restoring a 1973 Datsun 240z and planning to repair the damaged dashboard. I have removed the entire dash and then using a heat gun I have removed the entire dash vinyl skin from the foam substrate. The foam substrate and metal frame structure is in fine condition with no cuts,cracks or other damage. So I have planned to reskin the dash with new vinyl by the use of a homebuilt thermo vacuum forming machine but I haven't been able to determine with certainty what the composition of the original vinyl was and what product would be correct to use as a replacement. I believe the original vinyl is of an ABS construction but I suppose it could also be PVC of some type. Is there some way you can help me to positively identify it and or choose a suitable replacement vinyl. I am hoping you might have some insight and suggestions as to the manufacturers, brandname and or codes,product#s etc. I think Professional Plastics have ABS sheet stock and or rolls in the proper thickness and haircell texture but I am not sure if this would be the best product to use and I am also concerned about UV properties. I suppose this may be beyond the scope of your regular repair questions but I'm hoping your experience might offer some helpful insight. Of course any helpful info is much appreciated.
Thanks
zedhead
ANSWER: thank you for your question Zedhead. That skin in made of >PVC< and the foamy substrate of Polyurethane. I ignore what tradenames are available in Canada but the important thing is to get some integral skin like the one upholsterers use in marine grade applications. By doing so, you may be buying UV treated material. Do not use any epoxy based adhesive... go for any good contact adhesive as the one used by shoemakers ( toluene based). Normally, manufacturers make use of >ABS< in solid injected or thermoformed parts as in consoles, box glove lids, trays and so on. I will appreciate if you are so kind to send before and after pictures of the project to my mail :
manual@bumper2bumperplasticsrepair.com. Thanks again for considering automotive plastics repair a responsible eco- alternative.
Make sure to execute that operation in clean, free of dust, grease and water surfaces !
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QUESTION: Thank you very much for the prompt and helpful answer. This is the first time I have ever used the All Experts site and I must say I am impressed. Since asking my original question I tried a couple of things in order to Id the cover material and I believe you are correct about it being PVC.
While awaiting your response I decided to test samples of the original cover material with common plumbers solvent cements to see what effect each had and found no effect with the ABS cement but there was some softening of the material when exposed to the CPVC cement that I had lying around. I am assuming (please correct me if I'm wrong)that PVC & CPVC plastics are effected similarly. I guess as a follow up to my earlier question I am wondering if you recommend applying adhesive to the entire foam core prior to the vacuum forming or only along the edges and backside areas of the foam when trimming off the extra material. I know that a contact adhesive was used along all the edges and anywhere that the vinyl material wrapped around to the backside of the foam but I cant be sure that it was used over the entire foam core as it seemed to come off the core quite easily and without any damage to the foam when heated enough. I'm just not sure applying contact adhesive is advisable or not. It would have to be applied to both the foam core and the cover material and I wonder if that will have any negative effect on the vacuum forming process. Do you think that it would ball up under the vinyl or otherwise effect the smooth laying/stretching of the vinyl. Also I was hoping you might have some suggestions regarding specific suppliers you might be aware of regardless of their country of origin with regards to obtaining the correct PVC/vinyl material as well as adhesives and even any info regarding the specific type and density of the polyurethane that makes up the foam core and what glue/adhesives one would use to make repairs if required. The reason I ask is that although the core I have already stripped is virtually perfect I have two additional dashes from parts cars that I may refinish as well assuming I am successful in this endeavor!I mean I have to build the vacuum former I might as well get as much out of it as I can. I want to thank you again in advance for any and all advise you can offer and I sincerely hope/intend to be able to send you the before and after pics of a successful refinish. However I do think it will require some patience on your part because speed is probably not my best virtue when it comes to this project.
Zedhead
AnswerOK, remember that polyvinilydene chloride >CPVC< is used in hot water tubing and >PVC< in cold water installation. Therefore, if you find that the former is a good adhesive for this application, then use it...(in summer days, sometimes the heat inside a car with closed windows may reach up to 80°C - I have measured this temp. myself and the dash board and the steering wheel are untouchable!) In fact, I have never used plumber products in automotive projects but if it works, make some destructive tests with discarded dashes to see the real power of the cement. You may need to get, let me insist, MARINE GRADE polyvinyl skin material. Find a distribuitor and with some luck, you may obtain a free sample to test.
the foam core is made of >PUR< closed cell foam. If I were you, I would try just glueing as you say in the edges backside. by doing so, you minimize the negative effect the solvent has in the skin.
Take your time, test as many skins and adhesives as you can until you get the suitable combination.
I am really sorry for not recommending specific brands but the web may offer a great deal of local suppliers.
The heat gun may as well, be of used when installing the final skin, in the same way it did when stripping it out. it may assist you to get rid of inconvinient tensions and stress.
The days of those wonderful Datsuns are gone, as those of the Nikkei index around 40.000 points back in the 90's Vs just about 10.000 today...in summary, not even in Japan you can get such special material.
good luck!
